I used to work in a trailer park for my parents. Quite often, people would start using methamphetamine, begin to fall behind on rent and get evicted. Whenever we evicted someone their trailer was usually too torn to shit to actually do anything useful with it. Essentially, to prevent having a pile o' shit trailer in the middle of the park, we'd buy it from them and just tear it down.
Anyway, the the scary/creepy part. Many of these occupants had children. More than half of all of all of the children's rooms I found had locks on the doors, from the outside. Inside the children's rooms, it was always quite evident that the kids would sometimes be locked inside for days at a time, due to the "bathroom" corners that would sometimes appear. The doors on the insides of the rooms typically had scratch marks along the edge of the door and the door frame.
Getting rid of all of the stuff inside before beginning demolition always frightened me. I was always afraid that I'd end up finding a dead child somewhere among the filth. It never happened, but the odds of it potentially happening were, in my opinion, quite high.