It all typically starts with a family and a house. Perhaps they bought a new one. Maybe they inherited it. They've likely just moved to town and are new in the neighborhood. That's why they didn't hear the horrifying story of what happened in this house before they moved in.
Whatever the set up may be, one of the scariest villains to grace film and television is sometimes not a character at all: it's the house (and on occasion, the apartment). And just what can a house do? Lock you in. Let its lights flicker off and on. Lure you into the basement. Drip blood from the ceilings and the walls. It can get dark.
Usually, there's an angry spirit or demon behind the creepy stuff a house does to scare us, like anthropomorphizing an inanimate object into the face of our terror. But that doesn't make any of these haunted houses even the least bit less horrifying.
We're not going to live in any of these joints...