At my elementary school, in the fifth grade, my friend and I decided to do something for halloween. We went into the girls room,made sure it was empty and said thirteen times "If there is anyone here, let your presence be known." we heard tapping on an empty stall and something that sounded like a little girl sniffling.
We told my friend's brother about this, and he showed us his old yearbook. On page seventeen, was an obituary for a little girl that had fallen off the monkey bars and cracked her skull open. She died on the playground.
It's an urban legend at that school that she was buried beneath the sandbox and haunts the school, lonely.
And that's about all the interesting ones I have, so I hope that was detailed enough. OTL long post is long.