I never saw one, but I heard them.

I used to work for the City of Pensacola, FL as the overnight computer operator. There were two sites I worked, the old City Hall and the City Hall Annex. They were across a parking lot from each other.

Old City Hall, now the T T Wentworth Jr Museum

The Old City Hall was haunted. The elevator would run by itself several times a night, the computers would turn themselves off and on, and you could hear footsteps on floors you weren’t on, when no one else was in the building.

The Annex wasn’t exactly haunted, but one side overlooked a site where slaves were sold. I’ve heard the auctioneer’s chant several times, in the middle of the night when there was no one around.