I created this case to fit a Sonoff Basic V1.0 board into a standard switch box, using electrical tape seemed wrong. You need to modify the Sonoff, do so at your own risk. It will fit directly behind a standard wall switch in the case. You can use GPIO3 and GND as the switching leads. So far they have worked great for the past couple weeks with no problems. It seems to fit better than a Shelly 1 in this case, I have tried both.