My '79 Ford E-150 (with only 110,000 original miles) has the ignition switch in the dash. The first time I try to start it after it sits overnight the key won't turn the ignition cylinder. It acts like it's jammed and I have to giggle the key and work it back and forth for several minutes before it finally turns. It's parked outside overnight (too tall to fit under the garage door) and it doesn't matter what the temperature is out.
After I drive it awhile it seems to be okay for the rest of the day. It's been a bit notchy for a long time and lately it's been worse. It's like that with the spare key so I don't think it's a worn key issue.