You were born there as well Old Cat. Time to think, ahem, outside the box.
So who’s bedroom is it? That gizmo looks like some kind of guage, maybe a plaster thickness guage??????
Actually it isn’t a bedroom, it’s a library. And that’s another big hint.
And the gizmo is not a gauge. Nice try though.
Mick - getting warmer. No electricity of any kind involved though, AC, DC, high or low voltage. Remember: the gizmo can be replaced with a narrow strip of plywood that works just as good if not better.