There is no scientific evidence that ghosts exist. There's a restaurant near me that is supposed to be haunted, but it doesn't pretend to be haunted at lunch time, because that would scare the old people who eat there. It pretends to be haunted at dinner time, but employees tap on the walls to get the people at the restaurant excited about ghosts. I went there with lots of family members around Christmas one year, for lunch, and the teenage boys were disappointed that there weren't any ghosts or tapping sounds.

Scary things can happen, but they're not ghosts.