ignition switch problems

[kdeerman]

When I bought my 2006 GMC Sierra a couple of months ago, owner said he had changed ignition switch. The key is different from door key.

 

When key is removed and door is open, the bell dings as if key was still in ignition. When I press the door lock button, sometimes the driver door will unlock itself, as if the key is still in the ignition switch. Any ideas what my problem may be?

Thanks.