Never Wake Up a Sleepwalker

Did you know what waking up a Sleepwalker will cause severe shock, and even death to the person?

Well... no, that's not actually true - it's an old wives' tale that still persists despite scientific evidence to the contrary. However, in TV-land, no one has heard this update (and some media predate this myth being busted) and will continually dance around whatever strange or frightening behaviors the sleeper exhibits.

Never mind that the sleepwalkers half the time tend to wander off into pretty dangerous situations completely unawares, where one would think that waking up the person would be much less dangerous then risk slipping up and letting that one crocodile eat them.

But nope. It's too dangerous.

To add insult to injury, the sleepwalker will often walk right into bed, and wake up bright-eyed and bushy-tailed while their companion collapsed from exhaustion.

Comic Books

 * In Power Pack, the children bring Franklin back to Avengers Mansion after witnessing the Morlock Massacre. When the adults find out about this, Franklin claims he was sleepwalking, and the other children say that they didn't wake him because it would be dangerous.
 * One Archie comic has Jughead, for some unexplained reason, sleepwalk through almost all of his entire school day. To avoid waking him up, the teachers give all of their students tests. During lunch, Jughead stays asleep but eats the food off of everyone's trays. He eventually wakes up when the school bell rings, suffering from no ill effects. The other students aren't very happy.

Literature
""The Bursar sleepwalks most nights, you know." "Does he? Tempting...""
 * In Interesting Times, one of the wizards says that his grandmother always claimed that if you woke a sleepwalker their legs would fall off. A more skeptical wizard asks "How many times did she see it happen?"

Live-Action TV

 * Averted in Desperate Housewives: Susan finds Orson standing on her front lawn naked and muttering to himself. Once she figures out he's sleepwalking, she slaps him awake.

Video Games

 * In Day of the Tentacle, Bernard will refuse to awake Dr. Fred because he has heard it is very bad to wake up a sleepwalker.
 * One of the play modes in the old NES game Gyromite involves moving pistons up and down to protect a sleepwalking scientist.

Web Comics

 * In Girls Next Door, Erik advises Sarah not to wake Christine when she finds her sleepwalking toward his room for some late-night music lessons. Sarah dryly informs him that modern science has disproved that notion, then makes him promise to forget the potential trauma and just dump a bucket of cold water on her if he ever finds her sleepwalking toward Jareth's room.

Western Animation

 * Daisy Duck once had to race ahead of her somnambulist boyfriend Donald to remove obstacles out of his way, which considering he was doing gravity-defying tricks such as climbing up walls, was quite a feat.
 * Bluto and Popeye had to join forces to save Olive Oyl from herself in "A Dream Walking", especially once she wandered into a construction site.
 * Merrie Melodies:
 * One short involved a Fox disguising itself as a Guard Dog using this trope to smuggle chickens out, counting on the real Guard Dog's fear of causing him to his advantage.
 * Another, "The Unbearable Bear" featuring Sniffles the Mouse, involves a policeman chasing a burglar in his own home, but both parties trying to stay quiet because the policeman's wife is sleepwalking. Though it's more because they're both afraid of what she'll do to them if she wakes up.