93 silverado z71 250,000 miles. A friend of mine was backing in my truck for me and I noticed my backup lights werent on. A little bit after, he backed in my truck again, and the lights were on. The next day when I went to work in the morning, I noticed that my ignition wouldnt turn all the way back after I shut the truck off.... so my key ended up getting stuck. I moved the shifter up and the ignition turned and I was finally able to get my key out. This same thing has happened to my ignition about 4 times. I always have to grab the shifter and move it up a touch to get my key out! This ignition thing happened after I went off roading. I was twisting and slamming in the ruts and mud. I changed both backup lights about a month ago.

Do you think its the backup light switch or the shifter?