There was this glow-in-the-dark paperback Halloween book I had as a child, I couldn't even begin to guess how old it was.

I remember it was a story about a boy who wanted the perfect pumpkin for a jack-o-lantern, and someone, his grandfather maybe, told him to go to the house of the Snaggletooth Witch. He described the way to get there, but told the boy that if the witch smiled at him and showed her snaggletooth, he had to run home.

I've been looking for a copy of this book for ages with no luck. Sound familiar to anyone? Thank you!