I remember watching a movie in first or second grade, but because it was so long ago, I can't remember many details, or the title.
I've tried searching the net for this, and can't seem to find any films matching my description.

Here's what I remember:
A group of friends go trick or treating (maybe three kids, possibly two boys and one girl), and they see their friend dressed as a ghost (his name might have been Jimmy). They call him over, and he runs away or disappears. They later discover it was his ghost, he had been hit by a car while on his bike.
They manage to make a deal with a grim-reaper type of creature to perform tasks to save the boy.
In the end, they save the him.

It's called 'The Halloween Tree'. It was based on a book of the same name by Ray Bradbury.
I was hunting this movie down a couple of years ago too and it drove me up the wall that I couldn't remember.

Thank you!