Totally agree about using a relay also. I would use a 240-24 volt
transformer and a 24 volt contactor. With 24 volt, there would be less
of a shock hazard and you could use pretty much any kind of wire between
the float switch and relay-- thermostat wire, even telephone wire (use
the kind with 4 wires and tie wires together so you have a pair of two
wires paired together. Larry