My 1994 Ford Probe won't start?

my boyfiend drove it today and when we were on the highway, the check engine light came on. I couldnt smell anything and it wasnt driving wierd. When we got to where we were going he shut the car off and started it again, no problems what so ever and the light was gone! we drove it home a few hours later. We pulled into the drive way and he shut it off. i ran inside to get something and i came back out and he used the switch to lock me out. (Which means everything was working fine!!!) then he unlocked it and i got in. He tried to start it and now i have no power. Nothing electrical works and it won't even turn over. This car has been nursed back to health after sitting for 8 months. I just got this car in early march and ALREADY i have rewired all speakers, rewired my switchboard that turns rear defrost and wipers etc on. Ive replaced both door panels and unwired his "wile-e-coyote" job of a sub and amp. This car is my baby. it drives awesome except for an idle problem. When we push the clutch in the RPM's will drive up and down. Never going more than 2000 RPM's sometimes it wont do this. The car smokes when we turn it on. So my main problem is my no power situation. but if you have ANY clue as to what's going on please help. if you only think you know whats going on, dont bother, i need people with experience. I'm afraid of an engine fire. :( ive heard of fires starting with a "electrical phantom" like my car has. Could it be a fuse?? HELP!!!!