They both have the exact same two wire connecter on them.
I bought the Coolant Temp sensor but when I went to replace it, the threads were too small. It wouldn't fit the thermostat housing.
So I looked at the Radiator Fan switch, and it had the proper size threads, but was a little bit longer.
All the manuals I've looked at only make it more confusing, cuz one will call it a sensor and the other will it a switch.