Policemen , what is the scariest thing found in a sweep of a house?

I've got a cousin who's been on the force for a good while now, and honestly, the stuff he's told me over a few beers would give anyone nightmares. He once mentioned a sweep where they were clearing out a place that looked totally abandoned from the outside. The scariest thing wasn't some fancy weapon or drug stash, but finding a room that had been completely boarded up from the inside, like someone had been living in a secret space between the walls for months without anyone ever knowing.

Another time he was talking about a raid where they found a basement filled with hundreds of dolls, all arranged in a perfect circle facing the center of the room. It sounds like something straight out of a horror movie, but for guys doing those sweeps, it's just the weird, unsettling reality of what people keep behind closed doors. You walk in expecting a routine search and end up feeling like the walls are watching you, which is honestly way worse than finding a gun.