Well first things first test the switch, the switch IIRC is momentary push to make, personally i doubt its the switch but thats the first thing u want to check (the switch wouldnt ever make the wiring get hot).

What sort of state is the screen in? Ive seen on a lot of the Escorts/Orions the front screen starts to deteriorate after some years (going white around the edges etc),may well be the screen!