My overflow failed today :(

[Son Of Skyline]

I just came home to see a perfectly working system, minus 4 gallons of water from my sump, and apparently 4 gallons of water in my carpet. It seems that my external overflow had failed for a short time, sending water cascading over the top of my tank, but then started working again before my sump went dry. I looked for signs of plugging from a hermit crab perhaps, but there was no evidence. All I can see is the clear trail of salt water from the top of the tank down and onto the floor. From the size of these water marks it looks like this was a pretty dramatic event. I live in an apartment and I'm just hoping no water leaked down into the unit under me.

Is there a simple way to rig up a water on the floor sensor to my return pump so that the return pump shuts off as soon as water starts to flow over the tank onto the floor? I did some searching but all I seem to read about are audible alarms and emails sent if the water sensor goes off. I just want it to cut my return if the tank starts overflowing.

Thanks!!