The Case of the Giggling GhostPaperback - 2002
Mary-Kate and Ashley are excited to attend their town's annual Halloween Carnival. Every year, the carnival's proceeds go to charity -- but this year, few people are riding the rides or playing the games. That's because there's a ghost at the carnival that's scaring all the kids away!
The girls must figure out who or what the spectre is -- and how to get rid of it -- or the carnival doesn't stand a ghost of a chance!