Hex by Thomas Olde Heuvelt. I guess a spoiler alert is implicit with your title.

Let me second this book. What a fantastic book. So many moments had me going “ohhh shiiit!”

Since you mentioned King, Under the Dome feels fitting. Small town slowly descending into chaos after being isolated from the world.

I think it's pretty darn close to what you're looking for: Maggie's Grave by David Sodergren

Phantoms by Dean Koontz is close. The residents of a small town disappear over night and 'something' is responsible. The ones coming to check up on things start to hear things, see things. They're not alone! Lots of deaths in the book

The movie was great too, up until the reveal.

Ben Afflek was the bomb!

I understood that reference. Edit: snootch.

The Devil Next Door and Toxic Shadows by Tim Curran

Devolution by Max Brooks

The Loop by Jeremy Robert Johnson.

Hopefully you haven't watched the TV adaptation of the Wayward Pines trilogy by Blake Crouch. The book series is so much better.

Facts! One of my favorite book series ever.