No brake lights and a hard pedal, but then...

[Joesprocket]

So while i was out driving around in this awesome east coast weather I noticed that my brake lights weren't coming on when braking. Tail lights yes, blinkers yes, but no brake lights. I checked all wiring, fuse and bulbs but no luck. I hit frustration and mashed the brake pedal and not only did the resistance in the pedal get softer after that but the lights also started working. ... huh???

The truck has a brake booster installed by the PO but I feel like this is may be a problem that probably warrants a bigger solve other than mashing the pedal if the lights don't work.

Also - i should mention throughout all of this i havnt had any issues with the truck coming to a stop or general braking while driving.

little help?