I've seen something like a ghost once. I was in this abonded place called "Jamaica" it's near AMC 18 in Lawrenceville.
And I was just starring in front of me at the ground and something like moved out of the ground and leaped forward away from me and disapeared. I was the only one to see it from all 3 of my friends that were with me. It was only like a 2 second thing.