Help! Need "Scary" Ghost Stories by Halloween!

Background: This Halloween I’m volunteering with a nearby hospital to have a “safe” Halloween for children living in unsafe neighborhoods. It’s a good cause and sounds like a fun idea.

That said, my task is a simple one: I’m to escort the kids from school on the bus to the site location and make sure they all arrive safe and sound, and ready to have a fun Halloween, filled with haunted houses, scary mazes, and arts and crafts.

That said, I’m also supposed to tell them “Scary stories” along the way.
My problem? I’ve been reading Stephen King novels since the age of 8, as the other stuff was just not scary enough as a child. So I don’t really know any age appropriate Halloween “Scary Stories” for middle schoolers- or at least I don’t think I do. I could dumb down some of the stories I’ve read, and make it safe for kids, but even then, I don’t really know how “Scary” is too scary for these kids.

So Dopers, I come to you with open arms asking for Treats:
Can you tell me some of your Favorite Scary Stories that I could tell a group of children in Middle school? **
I don’t want to bore them with mild boring stuff, but I don’t want to scare the crap out of them (at least not litterally). Any Suggestions from you Dopers?

One of my favorites as a kid was the tale of the stolen liver. There are several variations. One can be found here:

Usborne book of scary stories are worth a look into.