@B-train and
@Donal are on to something. My interior lights shut down after approximately 15-20 seconds and the radio will play for 10 minutes each time, unless I open the door. At one time, I had a problem of hearing the chime noise that happens when you leave your key in ignition and open the door, even though my key was out. IMO, easy to do and inexpensive ignition switch could be an intermittent cause and can try that. Make sure the new switch has the updated sign of a grey plate on the switch body. Plenty of you tube videos show how to change it. If your old switch is all black, it is the old design. Very important to match the position of the gear teeth to where yours are when you remove old switch. I have done it enough on mine and my girl's 2002 TrailBlazer, that I can change them out in about 15-20 minutes.
When my chime was going off, even with key out, I had to insert the key and cycle the switch/key again, to get it to stop chiming.