I've had my 96 cherokee since August and just noticed this under the dash.
Obviously aftermarket, any idea what it is?

 

As best as I can tell it is near center of the dash...may be some cabling from a previous stereo/nav/dvd...best I can come up with...

 

A friend had one of those in his truck years ago. It was a anti-theft device. There was a plastic key with a printed circuit on it you put in the slot and then it was a runner. Whether it worked or not, it was pulled and round filed.

 

Looks like a breathalyzer port. Looks like the one on my father in laws Acura.