When I came home from work on friday my radio would not shut off when I turned the key off. I could take the key out completely and it wouldn't shut off. After a few seconds it went off. Sometimes it will shut off and sometimes it won't. I've had to turn it off with the switch manually to prevent my battery from being drained. What could it be? I know it's a short and I was thinking maybe the ignition switch cause if I jiggle the key a bit it cuts off right away. Anything else?