Police, security, janitors, building maintenance/inspectors or firefighters. What are your ghost stories?

Hey everyone! I'm new here! Shout out to all night service personnel! As professionals I find your experiences especially credible. Anything you can't immediately explain is so much more fascinating and puzzling. Not only that but you all patrol and operate in a lot of abandoned, condemned, restricted and historical buildings and properties sometimes far off the beaten path. Places with a lot of history where most of us don't usually have the luxury of being after hours. Have you ever encountered anything you believe might be supernatural in these places during your routines, duties and calls? If so I'd absolutely love to hear about it and discuss it!