Finding a book - a satanic mill

Cafe Society
1

I’m trying to find a book I read many years ago. It’s about a boy/guy who goes to work for a mill where strange things happen - people use magic and stuff. Like, one man traces a symbol/rune in the air, and the room’s dust is cleaned. However, the boy/guy realizes that more sinister stuff is happening - people who work and live in the mill are being killed/sacrificed.

Anyone remember the name of this book?

Thanks in advance!

WRS

2

I used to own this book as a kid. Funny, it still pops into my head from time to time, too. It’s called “The Satanic Mill” (apparently it was translated from German and may have other titles in other languages). Here’s the amazon link:
Link
Apparently it’s out of print.