2happy s-10

I have a 1999 Chevy S-10 ZR2.

Recently the key chime has started to not want to shut off when it's supposed to. If I shut the truck off and remove the key, it still chimes, as if the key is still in it (with the door open). Any thoughts?

I'm not sure what to check electrically to figure out what's wrong.

Also, the vehicle had been sitting outside for many months...may have contributed if a ground problem?