The switch is actually on the choke lever. I have a '77 US GTB and my light had been wired to the aerial switch. I rewired it to work correctly. Someone had replaced my choke lever in the past so I ended up fabricating a kind of sliding contact so that everything worked. Now, that said, I never use the choke since I am paranoid about one or more levers sticking open and making the car run overly rich. I just use my foot to keep it running for a couple of minutes and then I am good to go.
