A few years back I was working at a home for troubled teens called Burlington. One night I was sitting in the hall monitor chair, I seen a figure walk across the hall in front of me, and go into a room that is padded for when the teens lose control. I got up, walked to the room, and it was empty.
I told the story to another worker there and he told me that he has seen the same thing. He had also seen a dog in the hallway playing and just disappear. Another worker told me that she has seen the same figure many times as well.