I have a funny experience to tell. This is the most recent one that happen last May 2012.
I currently work as an operator in a medical factory that specialized in making parts of small medical equipment (i.e. Pacemakers). During night shifts there are more or less than 8 people who work at the factory (sort of skeletal staff).
I work during graveyard shift and during one of my shift I felt a presence of an "unseen" behind me. "He" is keeping his distance although I know that he wants to come near me. At first I sent him a mental warning to stay away from me, in which he did. Every night I can feel him circling behind me but still keeping his distance, although (I think) he is trying to keep out of my sight. I only caught his shadow as he withdrew when I looked behind me so I can see him.
It's funny to feel him around trying to get closer but my warning still stands until I take pity on him (Hahaha!). So I gave up and tell him, "Okay, fine. You can come near but I don't want to see you" and he did.
I can feel him hovering around whenever I am using my microscope. I can feel that "he" is just curious on what I am doing. Sometimes it's annoying to have him hovering around me because it makes me think that someone is trying to sneak up on me (one of my workmates loves to do it), but at times I'm curious about "his" history, though I never really want to communicate with him (because it makes him attached to me which I don't really like).
Up until now I can feel him around me especially when I'm busy using the microscope, at which I can see him in my peripheral sight as a shadow (more like a dark gas).
I'm letting this curious "unseen" around me as long as I don't feel any threat from him. He can be helpful if my sneaky co-worker tries to sneak around to surprise me.