What kind of screw should I use to mount an electrical box inside a cabinet?
For box mounting I use 2 #8 pan/ washer head screws. All the ones I have seen are Phillips or square drive #2, but there may be straight. Inspectors like the square head #2 because usually only electricians use these so it can help you pass inspection. At least 3/4” but 1” is the max I normally buy because the next size is usually 1.5” and that’s too long, especially if no drywall (don’t want to drive a screw through a cable).