Here's on tat DID happen to me.
First, an illustration...
This terrible drawing shows a shelf. The triangle is the shelf in the corner of a room. The little rectangles divided in two are tiny house thingies resting on the shelf. The long rectangle is a painting hanging on the wall juuuust above it. You need to understand the positioning to understand what makes it so creepy.
One summer, I was staying at the beach house with a shelf set up like this in the corner of the living room. My cousins and I were playing Sorry, and the adults were on the patio, when the painting fell.
Not that weird right? It's not that much of a stretch to imagine the painting falling off of it so hook thingy. But, here's the creepy bit...
The houses did not move. At all.
The painting SHOULD have fallen down to the shelf and slid off onto the floor, knocking the houses off with it, but no. The painting landed on the floor, and the houses were not moved a bit.