Do I Remember What I Did Last Summer?
The people never use the lights, or even if they think of the lights, they will not work.
The world is dark and dark blue toned, even at noon. Or maybe everyone wears invisible blue-tinted contact lenses, a la Oz. (Invisible blue-tinted lenses would be my homage to The Invisble Pink Unicorn.)
If the kid says that there is something in the closet, or that there is something under its bed, then there definitely is.
Ordinary people may be killed, but the ghost-defeaters will always return (relatively) unscathed.
If it is a toss-up between the hot female, the cute kid and the obnoxious middle-aged man, guess who dies?
All females are good-looking with perfect figures and never ruin their make up even after a long terror-induced weep. All males are either rugged or stereotypical nerds. And everyone has flawless skin with no tumours/pimples/unsightly blemishes/et cetera.
You learn never to put any of your appendages into any hole (example Plumber cleaning out sink!), especially at night. Eurgh.
The neighbours do not notice shotgun blasts and screaming even if it is a tad late at night.
The cutest one does not die, but most, if not all, of her (unfortunately for them, less cute) friends meet with gruesome endings.
I have watched too much Supernatural over the last few days.

I’m lost…what the hell are you on about?