The Stars Did Wander Darkling by Colin Meloy

A suspenseful and atmospheric horror set in 1980s Oregon, perfect for fans of Stranger Things, Neil Gaiman, and Margaret Peterson Haddix, from New York Times bestselling author and the Decemberists' lead singer/songwriter, Colin Meloy.
Maybe Archie Coomes has been watching too many horror movies.
All of a sudden, the most ordinary things have taken on a sinister edge: a penny on a doormat. An odd man in a brown suit under a streetlamp. The persistent sound of an ax chopping in the middle of the night.
He keeps telling himself that this is Seaham, a sleepy seaside town where nothing ever happens. Or at least nothing did, until his dad's construction company opened up the cliff beneath the old—some say cursed—Langdon place.
Soon, though, he and his friends can't deny it: more and more of the adults in town are acting strangely. An ancient, long-buried evil has been unleashed upon the community, and it's up to the kids to stop it before it's too late. . . .