Radio not turning off, causing battery to drain

Radio not turning off, causing battery to drain I have a 2003 Dodge Caravan and the radio in it won’t turn off when I turn the vehicle off. The radio makes a clicking/humming sound when it’s off and causes the battery to die after a while. I’ve tore apart the center cluster to unplug the radio and DVD player as a temporary fix and I was wanting to see if I could get some help to find a fix. Thanks