I was adding a hidden coin switch to an arcade cabinet, and needed a bracket to hold the microswitch. I was using an odd microswitch, so I made the mounting bracket adjustable from 0 to about 5/16". I can easily alter the design to go farther, but it fits the standard Cherry microswitch and fits my needs for this project.

For my project, I used M3-18 pan head bolts, flat washers, and nuts, with Lock-Tite Blue threadlocker. Nylon-insert lock nuts would be preferred, but I bought a M3 kit and there's 270 nuts in it. (Cue outtakes from Kung Pow - Enter the Fist.) This also works with #4-40x3/4" bolts and nuts, but the standard 4-40 nuts are larger.

I attached the bracket to the arcade cabinet with 1/2" truss head screws, pre-drilled. The switch is actuated with a cut off galvanized roofing nail that sticks outside the cabinet less than 1/4".