Okay, not psychic, but my dad used to run ghost tours of the local area for years, I used to help by dressing up as whatever random character I could think up of and find a costume for (inevitably a buried alive bride due to the over-abundance of bridesmaid dresses at charity shops). We used to have the usual ghost when we lived in a pub (happens a lot in the UK, they tend to be really old buildings), it was quite funny, the cold spot where the old lady who died used to sit meant that the coffee machine wouldn't work when it was there, so we put the cordial there instead.
Anyway, there was a pub tour variation (I was 14 I think), where we took the tour customers into the various pub cellar, told the scary but true story, then knocked the lights off and I screamed a bit. Scared the hell out of me when another woman stood right next to me joined in...
When the lights went back on she said that something had torn out her newly pierced nose stud, but somehow the butterfly back was still in - anyone with pierced ears will tell you that if this happens with a piercing stud, there should be a piece of skin attached to the stud - they are really, really hard to undo. I was the only person stood next to her for 3m, and the stud was a good 4-5m away when found...
I don't believe ghosts etc are sentient beings (long theory attained due to spending too much time in haunted places from the age of 9), but that one was hard to explain...
BTW On the girls hearing high pitched noises, I can hear a shrill tone right before my mobile goes, and whenever a tv is on, esp. if muted. An anti-teenager alarm was marketed here a little while ago as people over 25 (although apparently not me?) cannot hear above a certain pitch. It got canned due to the civil liberties of kids to hang around on street corners at all hours was encroached upon or something.