What Is This Little Light?

I think that's part of the 'noise maker' alarm system. It's an option that some folks decided to go with even though the car is equipped with PATS from the factory.

I'm not an expert but I think these little alarm systems were mostly dealer installed. At any rate, there should be a number on the alarm box behind the light/dash. I recall someone on here saying that Audiovox bought the company that initially made those modules.

Look through your owner's manual and see if they included one of those "if so equipped" sections about a car alarm.