I just made my reservations for the Halloween Carnival at the Heritage Museum in Sandwich. It is supposed to be great and sells out every year.
It is $8 per person if you are not a museum member.
I may not be here for Halloween so I want to do something awesome with the kids as I love Halloween as much as they do. Go to the link and it describes the activities as not scary so I think it will be good for small kids too.