1997 Buick Park Avenue Question: Ignition Lock Cylinder/ Ignition Lock Electrical Assembly

My car dings after opening the door as if my keys are still in the ignition. The side and rear running lights also remain on until the system resets (20 min). After closing the door and then opening it back up, the dinging continues. I am not sure If I need to replace the lock assembly or the actual lock electrical assembly or both. What's the deal? Thanks!