Magnetic Medium

If a show is about characters who can see spirits or ghosts, the show can only stay interesting if they come in contact with them about Once an Episode. Now, one would think that, because usually even normal humans can sense these creatures a little ("Did anyone else get cold just now?" if nothing else), they wouldn't be all that common, or someone would have seen through the Weirdness Censor by now ("Why is it always so cold?"). Yet somehow, unfailingly, there these spirits are, every single week.

This is where the trope comes into play. If you're able to see ghosts or spirits, they're attracted to you. They may want you to become a Willing Channeler (or if you're uncooperative, a Meat Puppet) and, in more unfortunate forms of the condition, will want to eat you. Though there doesn't seem to be that much logic behind it, being able to see supernatural phenomena makes you a grand, shiny beacon for it to flock to you.

A very specific form of Weirdness Magnet. See also Supernaturally Delicious and Nutritious and Magic Is a Monster Magnet.

Anime and Manga

 * Ginko of Mushishi encounters a spirit ("mushi") every episode because it's his job to travel to places where they're causing mischief already, and he spends weeks of traveling between episodes to reach these locations. Mushi do indeed gather to Ginko if he stays in one location long enough, but that's used as a reason for him to keep moving after the job is done.
 * Watanuki of XXX Holic is told the spirits that are after him for his power that enables him to see them by Yuuko in the first volume. There's a rather large and chaotic (offscreen) scramble for his eye in a volume, indicating that there's considerable power to be gained from actually eating him. In this case, it's revealed to be because.
 * In Venus Versus Virus, being able to see a Virus also makes you a target for them, because Viruses specifically are attracted to people who can see them.
 * Hollows in Bleach like to eat ghosts and occasionally living humans in order to feed off their spiritual energy. Since only people with lots of spiritual energy can see ghosts, those same people tend to become prime targets for Hollows.
 * Partially subverted in Mokke, since while Shizuru can actually see the spirits, it's her younger sister Mizuki who gets haunted or even possessed by them.
 * Because Hell Teacher Nube's titular character is such a powerful spiritualist and renowned exorcist, Youkai and Obake often show up on his doorstep to make his life miserable... even if they just need help or sanctuary. His students, on the other hand, have the preternatural ability to attract the attention of malevolent hauntings.
 * Hyakkimaru from Dororo was born without traditional senses (because his father sold his body parts to 48 demons in exchange for power), but instead had a powerful sixth sense. This, naturally, made him a target for spirits and monsters of all kinds.
 * Guts borders this and Supernaturally Delicious and Nutritious. The Mark of Sacrifice on his neck compels spirits to eat him, but also lets him sense their presence. Anyone can see and fight these spirits - Guts's only advantage is being a Badass. Grows closer to Magnetic Medium when it turns out that Guts can also sense other supernatural creatures and pass through barriers designed to block Muggles without noticing.
 * Takashi Natsume of Natsume Yuujinchou tends to attract Ayakashi that only he can see for a number of reasons:
 * 1) He's in possession of a book (the Book of Friends) that happens to contain the name of (and therefore the power to command) hundreds of Ayakashi. Many Ayakashi either want it for themselves, or simply want their names out of the book.
 * 2) He's a dead-ringer for his grandmother Reiko, who spent most of her adolescence single-handedly making just about every Ayakashi in the region her bitch (hence why they're listed in the Book of Friends). Since most Ayakashi aren't very in tune with human sex differences or the passage of time, those with a score to settle instead take it up with him.
 * 3) He's Supernaturally Delicious and Nutritious.

Fan Works

 * In the Avatar: The Last Airbender fanfiction Embers, people who were attacked by spirits or deal with supernatural phenomena (shamans, benders, Dai Lee) on a regular basis, tend to attract spirits even more. This often leads them to become doom magnets as well. This means the lives of Aang (the main medium between humans and spirits), his friends (mostly strong benders and victims of the Avatar’s Weirdness Magnet zone) and Zuko (a strong bender and member of a family with massive bad Karma) have a tendency to get complicated very easily.

Film

 * Whoopi Goldberg's character in Ghost, Oda Mae Brown, attracted spirits because she could hear them. This is explained because originally she didn't know she had that ability until Sam showed up, and the ghosts began to flock to her when the word spread. Exactly who spread it remains a mystery for the ages.
 * Quite annoying to the main character of Ghost Town, as he can see them and hear them, and they want him to tie up their loose ends of life.

Literature

 * One of the rules of magic in Discworld is that people who are magical tend to attract magic things. And, at least in some cases, to be more than usually susceptible to it once it turns up, as in Soul Music. Bad combination.
 * Sarah Monette's character Kyle Murchison Booth brought this down on himself as a consequence of raising the dead -- the one thing you do not want to do as a citizen of a Cosmic Horror universe is draw that kind of attention to yourself.
 * In Women of the Otherworld, ghosts can see a glow around necromancers, and therefore are able to tell who can see and hear them. As a result, they seek out and pester such people when they want something.
 * Another necromancer/medium of sorts, in a teen series, really hated this, since not only could the ghosts notice that she could see and hear them (and vice versa) but they can physically interact with her too - which means that they can do her some serious harm, if they're unhappy.

Live-Action TV

 * The short-lived series Dead Last justified this: the bearers of the Talisman are the only ones that can see ghosts... and it's their duty to resolve their Unfinished Business. Thus the ghosts flock to them in order to get some help off this plane of existence.
 * Jennifer Love Hewitt's character in Ghost Whisperer, Melinda Gordon, could also see them every week like clockwork. Apparently ghost pass around information on who to go to for resolution. And are polite enough never to interrupt each other when one is already getting helped.
 * The same also goes for all the other shows of similar ilk.
 * The titular character from Medium exemplified this trope. Her daughters, being mediums themselves, attract the attention of a few deceased folks themselves on occasion. Once she gets outed to the public several seasons later, she starts getting a lot of attention from the living as well.

Tabletop Games

 * Psykers from Warhammer 40000 have a greater connection to the Warp, but are more likely to attract attention from the hellish beings that lurk there and are therefore more vulnerable to daemonic possession.
 * An unrelated feature by the same name in Warhammer 40k is the 'Real Man' rule that the models you play with have to play as represented- no more or less equipment and features than what is shown on the model. It can get nasty, especially with Stop Having Fun Guys.
 * Sin-Eaters have death sight. Ghosts can recognize those who have death sight. Do the math.

Video Games

 * An aspect of gameplay in The World Ends With You, as Noise (even the loose-cannon Taboo Noise) will only engage the player in battle if they "scan" them; i.e. actively look for them.

Web Comics

 * In PS 238, Satori Deacon can see ghosts and other supernatural phenomena, and hates this because as soon as a ghost realizes it, she'll get bombarded with requests from beyond the grave.
 * Antimony of Gunnerkrigg Court is actually described by a ghost as "attractive... like a magnet".
 * She's VERY literally a Magnetic Medium. Well...in training for the position of "Medium" anyway. (Medium here means "intermediary for communication between groups, some of which are otherworldly in nature" and Magnetic means...she's a Weirdness Magnet)
 * In Hanna Is Not a Boys Name, Toni confronts Hanna about this, saying there's something really weird about him and she wants to find out what it is. Apparently she's never met so may supernatural creatures in such a short time span before, and she is a supernatural creature.
 * In Hanna Is Not a Boys Name, Toni confronts Hanna about this, saying there's something really weird about him and she wants to find out what it is. Apparently she's never met so may supernatural creatures in such a short time span before, and she is a supernatural creature.