1964 Plymouth Barracuda headlight knob won't pull out from dash

Thanks for your help. I got into the wiring leading to the floor dimmer switch and tried to remove the connector from the switch. The dimmer switch came apart as I pulled on the connector. I cleaned the contacts and did a quick hot glue gun fix and headlights came on! I am off to the parts store to replace the dimmer switch. Thanks for everyone's help.