Spooky story, not saying ghost is real or anything but this happened to me.
Last time at uni, I used to stay up late in the student office alone to surf the net, play dota, stream shows and stuff. My office was separated from a neighboring office by a thin plywood partition and that office is always locked when there's nobody around. Anyway, nearly every morning at around 3, I would hear something knocking on the partition. It would spook me and I would quickly pack my stuff and go home. But after a while, I was less afraid because I was thinking maybe it was the rats that run around in the ceiling. So one morning, I was in the middle of a heated dota match when the knocking started. I decided to ignore it. The knocking continued, and I kept ignoring it. Then suddenly something slammed against the partition wall. It was loud enough that I jumped in my seat. Immediately left the match, packed my stuff, and went home. Never stayed past 3 am since.