2002 malibu blues..need help with electrical problems

I have a 2002 Malibu and the odometer light and the clock on the radio stay on when the car is switched off which kills the battery overnight. What causes this?

One way that could happen is if your interior light switch is on but totally dimmed down. The odometer light and clock don't dim, as near as I know.

One way that could happen is if your interior light switch is on but totally dimmed down. The odometer light and clock don't dim, as near as I know.

Actually the odometer and clock do dim with headlight application. The odometer and clock are on in the ACC. (accessory) position of the key. It sounds like ACC is always on and the problem may be in the keyswitch