On a seat switch on a poulan mower it has three wires are two of them grounds or one.
One wire comes in hot and goes out hot to the next switch in the series of safety switches this is known as the switched pair, and the other wire is the ground, get a ohm meter and see which wires are paired by pushing the switch while in ohm mode when the meter reads 0 ohms when the switch is pushed those are the switched wires.
It's probably one positive, one negative and one earth ground.
