I do use a similar switch but bought somewhere else. You can do it that way and it will work.
But I feel uneasy running an ac line pretty close to a water source for something that's diy even though i made it. I have mine connected to a dc source which triggers a relay to turn on.

Running it on a DC source relay is a much safer way of doing things but it can work with AC power as well just have to do it right as you wouldnt want it to fail or leak electricity.

I have a couple of ATO setups running with these switches inline on extension cables that powers my pumps. If you feel uncomfortable with the AC power, its only $3-5 (cost of the extension)to remove the switch instead of having a pump thats been tempered and you lose warranty.

From the 3 years ive used these switches ive never had one break on me so i would say they are fairly reliable switches