1. I literally live a few streets away from a supposed "haunted" house which is now empty but the last person who lived there - an elderly woman is now in a psychiatric ward.
She put several new born babies in a freezer in her basement and some of them (older ones) - she buried their remains in the front yard.
Nowadays the house is really dirty on the outside and run down from locals breaking in at night for "baby ghost sightings"
2. When I was in elementary school a mother drowned her son in the bathtub after giving him sleeping pills.
I didn't know him very well but one of the boys of my friend circle was close to him and we all ventured to the house where it happened to say goodbye and some of the others were convinced that we could talk to his ghost if we believed in it enough. It was kind of an eerie experience because we additionally scared each other in the dark.
3. For my new job I had to visit the city where the infamous cannibal Armin Meiwes (
https://en.m.wikipedia.org/wiki/Armin_Meiwes) lived. I've also been to his house.
Fun fact: He's a vegetarian now.