2004 Hyundai XG350 Car continued to run after it was shut o

I was out running errands today and I parked my car turned it off and the car engine continued to run after I turned it off. I was able to back the car out of the parking space a bit and pull it back in and tried shutting the car off again, and it worked and the car was fine. I'm wondering if it is the ignition switch. I heard they can't be repaired but replace. If it is the ignition switch how much would it cost to replace? Or is the problem something else?

Thanks for any help or advice