1999 Dodge Ram 1500 truck- When you turn off the truck and take the key out of the igination, the radio stays on and sometimes the overhead light stays on. This then drains the battery. What should I look for to fix and where should I look.:)

Replace the ignition switch and harness--not a difficult job. It will be similar to:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-2.html#post224652

Be sure to disconnect the negative battery cable first.