Do ghosts really exist?

Just the other day, I was biking in my neighborhood. All the kids believe this legend that says that one of the spooky-looking houses on our street is haunted. While I ped this house I saw a kid playing just outside of it. He had really really white skin. I freaked out! Then I noticed he had red hair and a whole lot of freckles. I freaked out some more! Did I just see a ghost?!