What is it?

Went to the boneyard yesterday to pick up a few parts. Was going for the wiring harness that lights the vanity mirrors. Well it was attached to a much bigger harness that was connected to a rectangular box on the headliner between the visors. What is this part? Is it the computer for the overhead console without the actual overhead console? Don't have a digital camera to take a pic.

both my 89 Pioneer and 88 Limited have this... IIRC it's called the "System Sentry" basically a keyless entry system. Neither have an overhead console, just that 2"x4"x1" 'box' up there between the visors.