ignition switch?

I don't know how I seem to screw up simple jobs but here it goes. I changed my fuel filter and hopped in the seat to drive it from my GF's garage to my house to wash. turned the key and heard the pump prime then when I turned it to start the battery went dead. Had a buddy come over and jump start it and got it started but he swears that he could smell hot electrical smell. The wire that goes to the top of the solenoid (the press on one) looks like it has a fresh burn in the outer jacket. The last time I drove it with the headlights on and the top/windows up every once and a while I would get a whiff of something hot. Could the ignition switch be bad and cause the battery to short?

i was all freaked out after seeing that wire and thinking that my switch was going to burn my car up that i never thought to check the battery connections! Ill do that first thing in the morning. I already have the new switch and the old one is still stamped with the ford logo, didnt they have a TSB on that? im going to change it anyway and have a look to make sure that the wires there are not burned. Thanks rd