I did a quick check for audiobooks with carnivals/parties/festivals in them and came across this. The main character is an illusionist working in a giant carnival. Her illusions are incredibly realistic, but not actually real, or so she thinks. Then one of them is somehow murdered. This is YA, so of course the illusionist heroine is the first illusionist to be born in a hundred years.
I have to admit, I probably would have passed this by if it weren't for Halloween Bingo. But I'm still slogging my way through my paper and e-books, so if I want that Creepy Carnivals square an audiobook seems like the best way to go. Between work-time listening and the trip back to the car dealership that I'll be making on Friday (a couple minor issues with my new car that I want them to look at), I should hopefully be able to finish it before the end of Halloween Bingo.