When I was 13 I went to a summer camp that was situated at a college campus. My family dropped me off late and I didn't have time to unpack in the dorm room. I figured I'd get it done the next day.
That night, I heard what I could have sworn was a woman sobbing and shouting for help in the middle of the night. I knew that was impossible because the entire building was used as a boy's dorm, but as the sound faded, I looked around the halls anyhow. Nothing there. I chalked it up to a dream or mild hallucination and went back to bed.
The next morning, I got up early due to the eerie night and set to unpacking. The second drawer I opened, I felt a cloth hooked into the back, virtually hidden. I pulled the drawer away and saw a silver pair of panties resting on a sheet of paper. The paper was about what to due in case of rape or sexual assault.
I never found out about the woman or how long the panties had been there; once I gave a statement, the investiagtion continued on without further comment, though I thought she was probably still alive.
I don't talk about that day much. I don't know that I believe in ghosts, per se, but I never forgot that maybe there's more to this world than we know about.