My family bought a penthouse apt back when i was in HS. We got it for like 50k under what it was worth. Turned out the previous owner was a music producer who had dissapeared. The guys body finally wound up being found months later, the way I remember it he had been tortured then shot multiple times.
Real sad stuff, we bought the apt from his mom who just wanted to be done with the whole thing. Anyway, my step dad and I started going daily to fix it up but I always felt uneasy about being there as if someone was watching me.
One day my step dad went down to the car to get some tools and left me alone. As i was there by myself I looked down the hallway that led down to the master bed room and I kid you not I saw a bright white silhoute appear from one side of the master bed room walking to the next, it stopped in the middle, turned and looked straight at me. I fucking froze, it wasnt like an evil kinda thing, he just looked at me for a few secs and then walked to the other side and disappeared. I freaked the fuck out and bolted for the elevator. This shit happened during the middle of the day, it was bright as can be so I knew what the fuck I saw but my step dad wouldn't believe me and laughed it off.
A couple days later while we were tearing down some built in shelves in one of the bedroom closets we found a notebook beloning to the previous owner and in it were love poems, lyrics and sketches. My mom told my step dad not to throw it away so we could give it to the guys mom. My step dad being a piece of shit threw it away.
After that creepy shit starded happening, lights turned on and off. Windows we had closed the previous day would now be open. These were hurricane force windows by the way, the kind that have latches and keys to them. So it was impossible for the wind to have opened them. My mom and I stopped helping with renovations after that and my step dad hired some guys he knew to come and finish, these guys lived pretty far away so my step dad told them to stay in the apt while the repairs were done.
Lights started turning on and off. We were damn frightened and were shivering.
They lasted two days, they called my step dad in a panic in the middle of the night saying they heard shit, saw shadows and that their alarm clock would go off at random times they hadn't set it too. My mom decided that was it and called in a priest to bless the house, we then burnt sage all through out for a couple of days with the windows open to clense and clear the apt. The creepy things stopped after that.
A few years later I ran into one of the guys and asked him what had happened in the apt that spooked him and he said doors were slamming in the middle of the night and they heard what sounded like things moving out in the laundry area. He said it was the scariest shit hed ever been apart of and wanted nothing to do with it.