Removed the right front fender liner to change spark plugs on my 2011 4.0 and found a strange ball attached with two narrow hoses plugged into it. What the heck is it?

 

vacuum ball for the HVAC system

 

Thank you. I assume that if I get the lines hooked up wrong I won't have air conditioning.

 

You would still have AC but it would only come out the Defrost vents.
Vacuum controls air vent direction, fresh/recycle air, and heater valve on engine bay heater hose.

Yes, the "ball" has a built-in check valve on one port so won't work if lines are reversed.