[Rakoontay]

There is a ghost or entity in the office where I work. I get here early in the morning before anyone else, and I have to turn my music on loud so I can't hear it.
It will be in locked rooms opening and closing drawers. It will be walking behind me.
Other co-workers joke about the ghost as well, and we've all had experiences with it.

I've told it out loud to go away, and it usually does, but only temporarily. How do I dis spell this entity for good? It's not really doing anything wrong, but it still creeps me out a little bit, as well as my co-workers.