I used to hate hanging objects, like power strips, that have hidden T-slots on the back. No matter how carefully I measured, I could never get the mounting screws in the right place
on the wall. Then I realized that I could make a perfect full-size copy of the pattern on standard 8-1/2 by 11-in. paper using my scanner and printer (a photocopy machine would
work, too). I taped the pattern where I wanted to mount the power strip, drilled the holes and set the screws. Shazam! It worked perfectly.