1973 cougar xr7 ignition problems

Hey guys I’m about at my wits end with the dam car the ignition has a mind of its own I can’t get it to start using the key one day it will work for about 3 trys and then stop and I’ll have to press the breaks or somthing now the headlight knob had become my ignition I have to pull the headlight knob out to start it as soon as I pull it out the starter starts turning over and the car will start with our the key in the ignition then it won’t turn off I’m about over it

What kind of ignition system is it?