Mine is that we have 3 elves that are brothers (we have 3 sons) and they are here while their mom and dad are extra busy during Christmas season. This is their vacation from elf school right now. Maybe you can send a letter from Santa and it say something about how to watch out b/c some of his elves seem to be getting into trouble in people houses while they are doing some second checking on the kids on Satna's list. Something like that. Or send a little glitter in a bag from santa telling the kids that it's special North Pole dust and if they sprinkle it over thier favorite stuffed animal (one each or how every many you want) then at night they can wake up and explore until 12/25 when the magic ends intil next year.
Great ideas! I especially love that they're on vacation from Elf school but their parents are busy! I'm going to borrow this! I am also planning to enlist help from the aunts and uncles (none of them have children) - they are a creative bunch.