1992 Geo Prism radiator thermo switch on radiator

Hi, having a time trying to find a replacement radiator thermo switch for my Geo. This malfunction causes radiator cooling fan to run constantly with car on. It requires a two prong plug on the switch. NAPA, Advance Auto and Rock Auto do not have the correct switches, I have tried them all. I am at a dead end unless somehow I can just take the switch with me the next time I try another auto parts store. I am running out of options here. Thanks for any input or information.