I havn't seen any cherokee's with this,i have a black half dome thing hanging from the headliner towards the windshield, above the rearview mirror, looks like a store security camera, but waaaaaay smaller, what is it???? il try and get a pic!

 

it's the receiver for a factory keyless entry.

 

I have that too and I used to be clueless as to what it was until I saw it on here

 

Its a hidden camera...
Lol just kidding, mines got it too its the keyless reciever as stated above...makes me mad i dont have the fob for it, would be so nice. Was gonna buy one but i hear they are kind of pricey to get programed.