4. They found a heap of baby skeletons
“Not a realtor, happened to some friends who bought a property, very old site, about 300 years old which had been part of a convent, the living room of the nuns exactly. The aforementioned place had been refurbished as small apartments/houses about 50 years ago.
They went to live there and there was some maintenance given to certain places of the property (the common areas) there was a wall which was slightly wider than the others, they began to give maintenance to that wall but the outer layer fell apart (due to the rain and age) while trying to fix that they found dozens of skeletons of babies, very little babies and very old little skeletons.
Well, authorities and historians came and went by, and they came to the conclusion that the nuns tossed their babies there right after giving birth to them, lord knows if they were alive or dead by then.” — Moonwarden666
5. There were blood stains on the walls
“Not a realtor, but when the sold sign went up on our last house our neighbor came over and said, ‘Now you’re moving out, would you like to know about your house’s history?’ Turned out the previous owner was a heroin dealer, who allowed his customers to shoot up in the living room – explains the brown arcs all over the walls when we stripped the wallpaper. He also used to pimp his wife out from an upstairs room (our then bedroom). Lovely.” — dgbgb
6. He killed himself inside of the house
“One of our sellers killed himself in their living room while we already had a buyer in place. Postponed the sale while the drywall was fixed. Didn’t have to disclose.” — insipidrose