re: Do you believe in ghosts?

Yes. St Joseph Notre Dame building. Where sisters of Notre Dame lived for many years in first half of 1900's.

The building was abandoned and used for storage for the school when i was in 8th grade. One morning a friend and I were sent across the street in a thunderstorm to
Retrieve a bookshelf to bring to main office.
We were only ones in building because everyone else was at church for the school mass (always tried to find ways out of going) and when we walked upstairs to get bookshelf all was well. We moved a pile of books off the shelf and started walking away with it. When we got to staircase we both felt a cold air sensation, and looked towards a stained glass door of the room we just came from and saw a shadow go across it. All the books we had taken off the shelf we got then got knocked over. We dropped the shelf and ran away as fast as possible.
After telling our story, and a few other similar stories from the past, including doors slamming without warning (which happened to a group of girls a few grades above me) school had building torn down about 3 years later.