Excellent idea - but why stop there? Since it's a shack - shop-man cave, why not go the full monty? Label each outlet and switch cover plate with the number of the circuit breaker that powers it. That way, if an outlet needs to be turned off, or goes dead, you just look at the cover plate, see the breaker number, and you know where to look. Same for a switched lighting fixture, etc. No guessing. ----- Reminds me of a story..... Years ago, in the early days of mobile TV camera units, there was a news team that would be sent to the various county courthouses/city halls to cover newsworthy court proceedings, etc. They'd set up in the hallway or lobby to try to interview people on the way in and out. In those days they needed serious lighting for the cameras to work indoors, and finding which breaker controlled which outlet was always an issue. In particular they needed to know the ampacity of a circuit so they didn't have a breaker trip in the middle of an interview. The tech guy on the crew had a homemade "breaker finder" - a heavy-duty plug with the hot, neutral and ground all strapped together! He'd "test" a suitable outlet by plugging in the "breaker finder" and going to the panel to see which breaker tripped, and its size. Worked like a charm..... until He did it one day at a county courthouse that was....old.....and should have had serious electrical work done years earlier. The "breaker finder" didn't trip the branch circuit breaker, which was frozen in the ON position. Instead, the lights got dim for several seconds and then the main breaker for a large part of the courthouse tripped - plunging several courtrooms into darkness while in use for serious criminal trials. The judges in those courtrooms were NOT amused.