Have you ever seen a ghost?

Ghosts ... immaterial or material beings?

Most of these appearances are due to physical phenomena such as static discharge, light reflections, shadows, some prankster who wants to play us a trick, ah yes, actual cases of poltergeist.

Religion holds that the dead can be wandering between two worlds, this material world and the other world, the spiritual.

I saw a ghost, clearly and maybe twelve or fifteen seconds, what it took for this spectrum through the nave of a church and go to get to the altar steps. I stood rooted to the spot by so many seconds until I could react and rush out. 

There was no more, so I have not witnessed more than my story (which is as it happened)