I installed the new switch today, and the brakes lights appear to be functioning normally again. Thank you! An ohm meter shows the "B" side contacts of the old switch are all shorted together.

Unfortunately the rear spoiler deployed while I was testing the new brake switch. I suspect the battery had been drained with the constant load from the brake lamps. The battery tested weak, so I will try charging it and replace it if necessary.

I will button everything back up and more fully test, as soon as I can find out where this stray spring on the bottom of my lower dash panel came from.

Thank you everyone for your help.