Creepiest thing I ever had happen to me was when I was 17. Was sitting on the toilet, TMI but you'll live, door was shut and I was home alone. Rest of the family went camping and I didn't want to go. No one was home but me and the door knob turns and the door opens itself. Fucking no one there. I'm like, "OK, I can ignore this, just finish your busi-" and then the door slammed itself shut. Scared me enough that I'm pretty sure I crapped out everything I had left. Got done, opened the door and went out in the living room to find the couch pillows flying between couches like they were being thrown and disembodied childish laughter. I proceeded promptly down into my basement room, locked the door and stayed there until my best friend texted he'd arrived and, of course, by that point what ever the fuck it was had stopped.