There is this game called The Werewolves of Miller’s Hollow. I have it and it looks like a lot of fun, but it’s a party game and to date we’ve never had a Halloween party with enough people to play. Here, though, is the basic idea (although this one is based on a slightly different game called Ultimate Werewolf:
This video is part of a huge Halloweek playlist from Geek & Sundry, which you should definitely watch all of because it’s all great.