You enter a study and see a lightbulb hanging on the bookshelf. You try all the switches in the room — nothing is turning it on. Remembering you’re in [lonesoulsurfer]’s home, you realize that you’re going to have to start yanking on every book in sight.
While often associated with the likes of Bat-caves and other complicated hidden passageways, turning a shelved book into a secret switch isn’t complex in its own right. [lonesoulsurfer] is basing their build on one by B.Light Design revolving around a fan switch, some aluminium strips, a block terminal, fishing line, a hinge, and — of course — a book with a dust jacket and something to trigger.
Bend the aluminium into an angle bracket and drill a hole to attach the fan switch — ensuring the whole is small enough to fit behind and not distinguish the book you’re using. Cutting the hinge to the size of the book and screwing a strip of aluminium to it, both this lever and the fan switch’s bracket are then mounted on the shelf. Once a length of fishing twine is tethered to the lever and fitted through the book’s pages to the fan switch — ensuring the line is taut — sliding the dust jacket back onto the book completes the disguised switch!
[lonesoulsurfer] is using this switch to trigger a battery powered light as messing with mains power is a whole other beast. Since the fan switch has enough spring to pull the book back into place, all that’s left is to befuddle and impress your friends next time they come ’round.