the witch who saved halloween

This book tells the story of a boy witch who longs to go to school with human kids, even though witches are usually only awake at night and sleep during the day. After some difficulty, he convinces his relatives to let him try. While at school, he and his new friends form a plan to deal with the pollution that has been causing witches as much trouble as it has been causing humans. Witches in this story are a separate race, having nothing to do with devil worship or anything else sinister. The main messages are about friendship and ecology. It's a shame this is now out of print, but at least you can get it used. Readers may also be interested in The Resident Witch, by the same author.