Last night there was a really bright white glow above my bed...was it a ghost ?

It's never happened before and my friend could see it too (she was next to me). We turned the light on and we couldn't see it anymore, then turned it off and it was gone. We continued to talk and looked back and it was there again. It seemed to be hovering and moving slightly. In regards to light sources, the door was closed and the windows allow no light to come through.. But it didn't look like a reflection.