There are all kinds of plug in the wall "energy saver" boxes. None of these save energy or do anything. I thought I'd buy a cheap one and modify it to actually save energy just for fun.

This is sold under different names "Stopwatt" "eocwatt pro" "Stop Watt", "Stop Eenergy Watt Power Smart Energy Saver", "Electricity svings box", etc. If it was that easy to "save energy", the power grid operators would already be implementing it.