it's basically your std gy6 layout (250cc of course) with IIRC a vertical cylinder,
but that doesn't matter at all
Anyways.. AFAIK the radiator sensor is NOT a switch, it's indeed a sensor (thermistor type)
Means it should change it's internal resistance based on the temperature.
the ECU then decides (based on the water temperature measured and the head temp if the fan should run or not)
that's why it's important to get a matching replacement, since there are two types,
one lowers the resistance when getting hot the other raises it's internal resistance..
use the wrong one and your radiator fan is either always on or will never run.
(depending on which one you need of course)
'sid