The long white arm

I took a nap this afternoon as there was no electricity (load shedding here). So in the dream I sit up on my bed and at that moment a long white arm pops down from the ceiling. I'm not startled at all. The hand gestures at me to hold it with my hand. At first Im a bit hesitant.  The hand gets impatient and again signals me to hold it. So I hold it. I don't feel anything on holding it. No sensation at all. I even tried smelling it (which I find silly now) but nothing. So the arm pulls me up and I go through the ceiling, expecting to see the next floor. But instead I'm at some lecture hall with some professor lecturing and there are humans and grays sitting and standing around the lecture hall. This is all I remember.