In the past I have purchased some current sensing switches on eBay when they come available at a good price. I use them to sense if a unit is ON or OFF. In the past there usually are not many people who bid on these items. I noticed that there are 12 identical Hawkeye H908 up for bid with nearly the same expiration time. Just search eBay with H908 to locate them. I am not connected in any way with the seller.