PS3 Controller (Right Trigger)

I don't know if its because I've played the PS3 extensively now that this is happened, but everytime I press on the right trigger it makes a squeeking noise, likes its not lubricated or something. My left trigger doesn't do that, is there anything I can do about that? Anyway to fix this? It isn't a big ploblem, just a tad annoying to hear and know that there might be something wrong, but anyways I can live with it.