Lots of things can make that happen. Like Hooligan said, bad sensor, could also be the wires that lead to the sensor, check and make sure they are in good shape. There are multiple things, have you been doing any offroading or flexing with the jeep that might have led up to this? Type the key words in the search engine on the sight, you'll find this is a pretty common problem and has multiple reasons and solutions. Good luck to ya!
I got this same scenario when the sensor wire got pulled from it's clip and eventually rubbed enough that it exposed the wires and cause the "christmas tree" to light up so it could be from something that you did earlier and showed up later. Best to just keep checking all around.
2007 JK Unlimited Sahara, Blacked Out
3.5 inch lift sitting on 35's
Poly Performance/Synergy Suspension Ball Joints
Smittybilt Oversized Tire Carrier