I use silicone fluid in my 300 C & F, and those brake light switches have a very short life especially with that fluid (I will never go back to regular brake fluid!).  I gave up and installed a brake switch and bracket from a 1970 Chrysler on my brake support so that the electric - mechanical switch rests against the brake pedal arm, just like in my 1970 Chrysler 300.  It was an easy installation, with no further problems.  I left the master cylinder mounted switch in place with its electrical leads so they look stock, and wired up the new mechanical switches to work.  No further problems.
Steve Albu