HELP. Ignition switch

I have a 76 dart sport when I got the car the ignition switch would pull out of the column every time I took the key out so I replaced the switch and it just pushed right in I didn't have to take the column apart and it worked fine until a week ago now when I turn the car off the switch won't go back far enough to take the key out is it the switch or do you think it's something in the column please pm me thanks