I was working on the interior of my car and wasn't able to complete the accessory installation that day. Knowing that the car had a battery saver that disconnects lights after 20 minutes if a door is left open, I didn't bother to close the driver's door that night. All the other lights had shut off, but when my wife went into the garage, she saw a light still shining under the drivers door.

I immediately opened the lamp assembly to this rogue courtesy light and disconnected it to avoid a dead battery in the morning. This light is underneath the interior door panel and is easy to miss. I'm assuming it's the same for the passenger door. Lesson: Don't rely on the battery saver to shut everything off, especially if you have incandescent bulbs that draw a lot of current!