Ring My Bell
If you work in a residential care facility, you know that it’s common for residents to push the mechanical call buttons that contact nurses and aides for help. So, on its own, there’s nothing weird at all about a resident calling for help, even in the middle of the night. Right?

But when a bell pushes itself, and there are no patients, doctors, or nurses around, it’s more than a little creepy. I don’t know about you, but I don’t think I’d be able to work in that place after that incident. To this day, the OP has never found an explanation for the mysterious bell ringing in the middle of the night.