Screw the Electric Bill!

""No, we don't have the lights on because it's dark. We have them on because the power company needs the money."

Unknown Movie Quote"

Ever notice that in TV land, people rarely use a light switch?

It doesn't matter which room of a house the character(s) currently occupy; when they move to another room, the lights are already on. And when they leave a room, the lights stay on. Sometimes, characters will even arrive home after a night out, and the lights in the house are already on. The only time the lights go out is when everyone goes to bed, or when darkness is essential to the scene (for instance, an allegedly amusing "fumbling about in the dark" sequence, or to facilitate The Reveal). Or, if a character does turn out the lights upon leaving a room, it's usually symbolic.

Most common in Sit Coms and Soap Operas, where it can be externally justified by the fact that, since such shows often employ Three Wall Sets depicting an "open" architecture, they utilize shared lighting rigs. Further, as anyone who has ever used a klieg light can tell you, big studio lights don't flick on and off in the same manner as 60-watt bulbs; they require long periods of warm-up and cool-down, and turning them on and off during a shoot could be distracting.

Furthermore, these sets will typically feature numerous practical lights (table/floor lamps, sconces, etc). No matter how many such lamps are present, every last one will be burning, day or night. This could be seen as perhaps an attempt to justify the amount of illumination the studio lights are pumping out.

One of the few times this trope gets a mention is the Christmas Episode, where there are so many more lights than usual that someone will feel the need to, er... hang a lampshade.

Of course, if they ever do switch off the lights, it's not like it gets dark anyway.

Live Action TV

 * A Two and A Half Men episode restored some comedy after a dramatic scene: Charlie, exhausted from the drama, turns out the light and climbs up to bed. Then, the camera pans to reveal the rest of the family, still at the dinner table, wondering what just happened.
 * Stargate Atlantis routinely displays the entire city lit up despite only having a few hundred people on it, and that they are constantly looking for new ZPM's to power the city.
 * Possibly justified by the Atlantis team bringing Naquadah reactors with them, and eventually having intergalactic starships, so they could just be flying in more Naquadah from home.
 * Lampshaded in an episode of Friends, after Joey sees how big the electric is, he quickly turns off the lights.
 * Lampshaded in Married With Children when Al asked his family why they need to have all the lights on.

Western Animation

 * Lampshaded in some of the audio commentaries of American Dad DVDs, where members of the production staff complain about a table lamp that seems to be left on permanently during the day. Remember, this is an animated show we're talking about.