I agree. I bought a little relay board a few years ago to get started on a project for controlling line voltage, but then I started to think: - Will the board

I agree. I bought a little relay board a few years ago to get started on a project for controlling line voltage, but then I started to think: - Will the board short if it happens to collect moisture, oil, dust, or lint? What if a bug is attracted to it? Will I even monitor the condition of the board? - Will the traces and relays heat up if I accidentally draw too much current through them? Will they degrade over time? - Is there a chance that vibration could loosen the board and make unintentional connections? I decided I probably could never answer these questions well enough to satisfy an insurance company. It doesn't matter that I have plenty of experience with line voltage; what matters is that I am not a licensed electrician. Therefore, at home, I only experiment with low voltage and low current, delegating all line voltage to UL listed devices.