The smiling spirits

Working in a warehouse infested with spirits.

Four year ago, I was posted to this warehouse. I work 8pm to 8am shift. On the first night was normal. On the second onward I could fast moving black shadow. Soon there was people standing in front of me and was smiling. Vanished after a few seconds. Soon the person came very close, just beside me, but since the person was only standing and vanish in a few seconds I just let it be. There were only five staff including myself, the warehouse has the size of a football field. In a week I can see this about two or three night, not every night I saw. So this sightings became a normal things.