Water sensor

Just google 'high water alarm" or similar. Or go to the hardware store and buy a sump pump switch, and hook whatever you want to it.

Bob

Tada! ..Thanks..I'm here all week! Jimi

I have something like this, at about this price. I attached the original sensor in the basement sink (which can fill up when it rains enough, including today (since I had forgotten to plug it) or might fill up if the drain clogged and the clothes washer put both the wash and rinse water into it) and I made another sensor (two pieces of metal on an insulator, glued to the side of it) for the sump pump pit. That way either sensor trips the alarm. I lengthened the wire from the sensor to the alarm so that it went from the basement, along the water pipe, to the cabinet below the sink, and put the alarm there.

Of course the battery went dead about 10 years ago, and I've been too "distracted" to replace it. But otherwise it is a very good system.

Actually the one I got 10 or 20 years ago requires one to move a switch to "test" to test the battery. They didn't have cheap low-battery alerts in those days. Even fancy things barely had them. (Maybe really fancy things had them, like thousand dollar video cameras. Electronic stuff quickly gets cheaper.)