I have a light switch that turns a wall socket on and off. Is there a way I could sense whether t...

I have a light switch that turns a wall socket on and off. Is there a way I could sense whether there's power going on and off with an Arduino or other circuit, then have that message go over wireless or into the ether or even the cloud?



(Granted, given a signal, transmitting the signal to another computer is a solved problem. I just want to know how to get the signal.)

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