I saw something similar in the hardware store and thought.. I can make that.
So I Did,
There is a recessed screw hole if you wish to screw mount - or i just used a little liquid nails/adhesive to the surface. Or you could use double sided tape.
I'd recommend printing in ABS or something with more strength and like 80% infill for strength. you SHOULDN'T need supports if printed flat as the bridge is small.
IF you you break them, go the heavy duty version - tough as nails
Cable slots in, cable tie holds in place.
Brim if printing many is my suggestion