Here’s an ultra simple method to wall mount your gadgets such as multi-gang extension cable, clocks, racks, router, smoke detectors and etc… Not all the devices comes with a mounting guide or a template. The traditional method was to trace the back of the device and then mark it on the wall to drill them. Here’s a more accurate way to get it right.
Just use a photocopy machine or a scanner to scan and print this at 100% or 1:1 ratio.
Use the printout as a guide – making sure of the direction of the keyhole mount (Larger hole is aligned to the bottom)
Screw the mounting screw directly on the paper
Once done, just rip the paper away and you can mount the device on the screws with perfect fittings.