Why is there a circuit board in my brake light?

I just went to replace my brake lights and instead of finding a bulb that I could replace there was another connector with wires going to circuit board inside the tail light. Its on both sides but looks slightly different on either side. On the passenger side you can see the circuit board components and where the wires from the connector are soldered to the circuit board (this is all inside the taillight). On the drive the side the connector is white and you can't see circuit board components, just a piece of gray plastic but it looks like there might be a green circuit board behind the plastic. The drive side has a wiring harness for the topper, but its not hooked up right now, thats a future project. Anyone else have a circuit board in the taillight and know why it's there? Whats the best way to get to the actual bulb?

 

The circuit board is for the LEDs. If it's an LED, it's voltage and current direction sensitive.

 

^ This. They are likely board mounted LEDs. I also see some resistors in there. It's likely just a simple circuit to make sure each individual LED in your tail light gets the right voltage.

Either that or that's your NSA tracker. It's too late. They know everything. Run.

 

Definitely too late. They already know...

Is it possible to replace the LEDs? Or am I going to have to buy a whole new taillight? It seems like the circuit board/LEDs are sealed inside the lens without an easy way to get in there.

 

Back in the day, when we needed to take apart a headlight (i know yours is a tail light) - we would bake it in the oven for about 6 minutes at 250 - and it would come right apart. You'd have to reseal everything, but just mentioning it.

 

Sealed, ran into this when I broke the lens and wanted to harvest the board.

 

You're not taking that tail light apart without breaking it.
Notice the "NAL" logo, it looks like NFL, but the A is squared off. I used to work for this company, they are in Salem, Illinois.
The tail light lens is either hot plate or vibration welded to the housing. The lens is PMMA (Acrylic) and the housing is likely ASA (Acrylonitrile Styrene Acrylic).
If I'm not mistaken, this part is not serviceable without getting creative.