|This has happened to me, but has always been fixed by mashing the joysticks, or turning of the console/controller. Try that first.|
If not, try using the controller you normally use for player 1 as player 2, and player 2's controller as player 1. That should point you to where the problem is stemming from.
Something also may have been spilled on your controller, or it simply might just be broken.
Can I put a question here?