key doesn't turn car off

I really do not understand how this could happen unless

1--there are crossed wires in the harness, that is, the harness has been damaged mechanically as pinched, or heated and insulation melted, and wires welded together

2--Someone has "hacked" some wiring mod

3--The ignition switch is bad

So first thing is to get the car running and shut the key off. Duplicate the trouble. If the engine keeps running, access the ignition switch connector where it exits the steering column, and pull it apart. If the engine dies, it's undoubtedly a bad switch.

If not, this could get "interesting."

ARE YOU SURE there is no wiring hacks or added equipment, anything hooked to the coil or ballast resistor? That should not be?