I had no trouble installing this GFCI socket but I seem to have received two faulty ones. The first one I ordered was clearly opened and most likely already returned by Revain (the box was torn and separated from the clear plastic part of the packaging). So I sent it back and got a replacement, which didn't work either. I think the light barrier sensor was defective on all devices. The output portion worked fine and powered the devices I had plugged into the outlet. The socket also functioned normally when the "Test" and "Reset" buttons were pressed, which means that the socket was connected correctly. But even in my pitch black bathroom, the night light never came on, making this product almost useless for me. There seem to be a few others who are having this problem, so it's a gamble if you can get one that actually works. After trying two of these and one from another brand I give up and just go back to my regular GFCI outlet which worked and is still working fine. It would be nice to have some light in the bathroom at night.