2009 Trailblazer - Ignition switch won't shut off completely. Can't remove key, power still on but car does turn off. This is an intermittent problem. any ideas out there?

Try spraying some WD40 in and around the ignition switch may help unstick ignition switch.

Try using some graphite or and anti seize product. And it that doesn't work I would take it to a Dealer near by. Im sure that it has a recall for that.

make sure you put the product on the key if the key can be removed

Bad ignition switch. I've had to replace mine 3 times in 2 1/2 years. Symptoms I had....radio and or interior lights would stay on after turning the vehicle off, getting out/closing the door, which of course will drain the battery. Eventually the key would get stuck in the ignition. I also had my vehicle completely shut down while going 55 on the highway. It wouldn't start with key but would start with the remote which is no good cause they automatically shut off when the key is not in the ignition and you attempt to put the vehicle in gear. It's a easy fix and costs me around $40. for a new switch.