72 Nova SS- engine will not shut off?

[RALLY]

I took my Nova for a ride. Car started great but after parking my car in the garage and turning off the ignition switch to off the car kept running. I then moving the switch to the start position and off back and forth a few times and engine still would not shut off. Does this sound like a bad ignition switch that is mounted on the lower steering column towards the floorboard? I know the switch up top has a rod that operates this ignition switch below. Does it sound like a bad switch? I did pull the ground on the battery after i stalled the engine to shut off and move the switch to the off and on positions about 5 times. Hooked up the ground on the battery and the car started and then shut off. Any input please? Thank you.