This is my college encounter that I had a good number of years ago now when I was studying computing for a couple of years at a local Tech college.
I was in the process of studying Computer Aided Drafting (CAD) and after completing the course I was awarded with a bursary, so I stayed on for another year doing my own thing learning as much as I could on computer graphics.
On a pretty hot summers afternoon, in the library (which is where the tech suite was) I was working away on a drawing project that demanded my full attention (not so easy when surrounded by some younger noisy students), when I happened to notice brighter light coming into view from my right as I faced the computer screen.
As I turned my head slightly to see what it was, I became aware that it was in fact a white round ball of light moving slowly across the room at about a couple of feet below ceiling height. It came across from the large windows side of the room and moved only gradually lifting up towards the left side of the room (on my left) and travelled right into the top corner of the ceiling and as it disappeared it made a fairly loud "bang" as it faded away through the corner of the ceiling leaving me very puzzled - as not one of the students surrounding where I was working seemed to have seen, or heard it.
After I finished studying for the day, I went up to the head of staff within the library recounting to her what I'd experienced during that afternoon, (half expecting her to act like she thought there might be something a bit "odd" with me), she unexpectedly told me that this had been reported to them on a number of occasions before which amazed me at the time. She also told me that there were men working above the library making changes to the electric wiring upstairs, but whether that had anything to do with it or not didn't seem to hold much relevance if in fact the same thing had occurred and been reported a number of times before.
So that was another encounter that I hadn't planned upon!