Do you know where to get a sensor that lays on the floor behind a refrige and warns of a water leak?

Question

I saw an ad on TV a while back showing a device that lays on the floor behind a refrigerator and warns you if your refrigerator water line starts to leak water. Need to know what it's called and where it can be bought.

Answer 1

This is one that is placed on the floor behind a washing machine. Wondering if you can use it for the fridge. Hope you can. You can check it out at the site below. It is from one of those as seen on tv ads.