Looking for a book about a Puritan town with a Twin Peaks-esque uncanniness that isn’t just about witches or devil worship

I’m looking for a “weird town with a dark secret” type of mystery book but it takes place in a Puritan town or similar (like an austere modest and pious town).

However, I’m not looking for a simple witch or “secretly devil worshipper” story. I’m looking for a “dark secret” that is a little more unique complex or unhinged, for example maybe they>!meet up in secret for a town orgy every friday!<

I know it’s a really specific request, I doubt there’s any book that fits it exactly

by QueenMackeral