What it says on the title. Mine was when I was 12 and I lived in a very haunted house which had some weird activity going on, like things moving out of place and pets freaking out. I was sitting in the computer, alone in the house, and suddenly I see a shadowy figure on the screen, just some meters away behind me, thinking was my mom I turned around and there was nothing, but the room had turned extremely cold suddenly. There was nothing behind me that could have been this shadow.
Worked at a laser tag place and everyone always said the arena area was haunted never really thought much of it though. There was one night I was turning off the arcade games and the switches were located in the staff room next to a door leading into the arena. As I started to flip the switches the door knob started to shake up and down rapidly. I ran out of the staff room and saw the other two workers sitting at the front desk. No one was in the arena.
Another instance at the same job I was fixing something in the arena in the morning as the tech and I heard someone walking up a ramp to another level of the arena. Only other person there was the owner who was in his office at the time.
Always creeped me out but it was fun to give everyone else a good scare from time to time.