Here's a thread on the 1928 light switch, and I show the plate you need setting on the blue background. The switch parts on the green background are for the March 1929 and later headlamps. Sacramento Vintage Ford wells the correct wiring harness for the 1928, and if you don't see it listed in their catalog, just tell them what you want. I ordered two for my early 29 and my 1928.
https://www.fordbarn.com/forum/showth...8+light+switch