Had a door jamb switch go bad on my "63" Starfire, after much searching I found that a 65-67 Mustang switch,that looks identical on the metal part that shows, fits the 7/8 in. hole. These switches are repro & are fairly cheap. On E-bay 2 for $18 inc. shipping. Had a junkyard try to sell me a used Olds one for $40.

 

Nice sub!

 

In case anyone needs to do this jamb switch swap there are a couple things that you need to do. 1st is the metal springs are held in place by tiny platic tabs that will break as soon as you try to push the switch in the hole. So put super-glue under the springs to weld them to the plastic body so those tabs don't break off. 2nd, you might have to squeeze the metal springs together a bit to get the switch in the hole and 3rd the switch will probably be a bit loose in the hole, go behind the door jamb with a flat screw driver and pry up the end of the spring, the end next to the bezel, until it rest on the inside of the jamb. This will hold it very tight. My car had blade type connectors and this switch takes pin type so you will have to change the connectors.