I have a wired 360 controller, I have had it for about 1-2 month. It is one of the microsoft ones not the crappy madcatz one. It will randomly press LT or RT, I have died numerous times from it does anyone know why it does this? It is one of these (this is not mine just a pic I found of one) One note here... It has just recently started doing it more often before it was like once every hour or two now its once every game or two.
Just sounds like general wear and tear. You might try opening it up and cleaning it. Otherwise, get a new controller.