Are most mental health facilities and hospitals haunted?

I hope not: Haunted health care facilities would pose a major problems for patients and chickens like me. I know these facilities often make for great horror movies, especially all the dark corridors. There's a lot of effort now to make hospitals more patient friendly, better lit with a warmer atmosphere.

Haunted: I would like to believe not. However, having worked at a state hospital during my residency training, i bagan to wonder back then.