you may have the wiring already there they stoped that in 96 i think so go look and see if you have the connectors, you can wire up the system your self its very easy... just stick the fog lights in plug them up with a plug that you may need from ford, then run the ground wire for each to the negative battery or somewhere there is a ground.
then run the power wires to a relay, then run the relay accesory wire to the switch then to the battery, and run the power wire for the realy to the battery, then you ground anything that needs it on the relay and switch.
you flip the switch it pulls power from the battery it goes though the switch and to the relay, this turns the relay on which then pulls power from the battery that goes though the relay and down to the fog lights and they come on. if you want to go one extra step instead of running the wire from the switch to the battery run it to the parking light amber's power wire so the fogs can only come on when the parking ambers are on.