We have a rather newer building, only a couple of years old, but it still has strange things happening. We share our unit with ICU and probably patients have passed away in all the rooms at one time or another. One night all the nurses kept asking if other nurses had adjusted the oxygen flows on their patients because they kept changing from what they had been set at. We all had it happen to at least a couple of our patients, all through the unit, all night long. It was so very strange.
Another time me and another nurse observed the TV turning off and on, off and on over and over again in an empty room. I went in and physically turned it off, only to have it turn off and on again as soon as I sat back down at the station. We thought maybe it was the remote that plugs into the wall (controls TV, call light, etc). We unplugged and plugged it back in, tested it out and it worked fine. Sat back down and the TV started doing its thing again. I called some other nurses over to witness and we were all creeped out. Finally one nurse went and unplugged the TV from the wall and that fixed the problem.
There is a very long corridor between two buildings that gets creepy at night. It is close to 1/4 mile long. Twice I have had the doors open for me at the end of the corridor before I had a chance to get close enough to swipe my badge to open the doors. No one in sight on either side of the doors.