Parking lights will not turn off even when the engine is shut off. I had to disconnect the battery, so as not to drain it. What is the problem and how can I fix it without having to take it to the dealer to get it fixed?

 

Sounds like a bad switch. Test it with a multimeter:

 

Does your car have an aftermarket alarm? My gf parking lights stays on because her alarm will sometimes act up and her lights won't shut off until she starts and shuts off the ignition.