I used to live in a small one level unit apartment in 1991. I didn't have a problem with any of my neighbors except this one 20-something guy who I'd always catch loitering around the back of my bedroom trying to look in my windows and listening in on my phone conversations. One time I caught him running away as I pulled back the curtain. I heard the gravel crunch before that. It was only a couple months before I wouldn't have to put up with that again.
But in some ways what happened that fall was worse.
I was interrupted in the middle of watching a show on TV by a bunch of noise outside. I went out and saw ambulances and cops everywhere. My landlady was standing outside her apartment smoking and watching them carry three bodies out to the ambulance on stretchers. I asked the cops what happened and they said they couldn't tell me. So I asked the landlady. She said the young guy who lived two doors down from me had shot and killed two men, then himself. That there had been an argument. There had also been another suicide in the apartment behind me, but I didn't know that at the time.
I moved out soon after that. I came back to the apartment where the suicide had occurred, still not aware or told by the manager about what had happened there. So I suspected nothing. To this day I'm not sure if the hauntings were the young man who had shot the two women and himself, the other guy who killed himself, or a combination of the two. It was only a couple weeks before things started happening. First, the bedroom had an ominous feeling that came and went. It never felt right. Then one night I awoke to see a man shaped skinny tall black cloudy thing hovering over me. My immediate response was to yell at it to back the f**k off. He floated backwards into the wall and I noticed "he" had no face. Three weeks later, it came back and sat on my bed and woke me up when I felt the weight and pressure. My legs even rolled into the indentation where I assumed the ghost butt was sitting. I was angry. How dare this creep come back to harass me? I forced myself out of the fear paralysis and woke up, sweating like a pig. He was gone. I moved out soon after that. BUT...
Three years later I babysat for my sister, who just happened to move into the apartment across from where the murders took place, a mere 20 feet away. Like I said, it was a small, L-shaped unit of apartments. One night at 1 am, when the kid was asleep down the hall, I saw a shadow come up behind the light in front of me. It turned the dimmer switch 3 times really slow off and on. I froze. I never told my sister about it either. I wasn't sure what she'd think as she was more religious than me and might overreact or disbelieve. I also didn't want to scare her because she had a baby in the house. I just hoped the ghosts or whatever they were were leaving them alone. I noticed she didn't live there much longer though.