2005 Grand Marquis Turn Signal cancel switch

I'm having a little trouble with my Father-in-laws 2005 Mercury Grand Marquis. The turn signals won't turn off after making a turn. They come on and work just fine but won't cancel themselves out, it must be done by hand. Is there something on the steering colum that trips the switch as it turns or is the problem in the switch unit itself. All flashers, fuses, and lights are working it just won't turn itself off. Any help would be greatly appreciated.
Thanks

More than likely it is the switch. It is easily replaced and not all that expensive.

Thanks. I wasn't sure. I will see if he wants me to replace the switch. You help is appreciated.
Mike