Question every new person asks.What is that light in the back that does not work?
I asked the same question.You can buy a working light from many sources and tie in as a brake lightl.Quick and easy.
You can get a harness with a swich and if you have a blanks where the 3 switches go it hooks up nicely.
You can get really stupid and hook up as the factory fog light is intended.This is how I hooked mine up.A lot more involved.
DIY:REAR Fog Light install with New harness for US spec 370Z + Radar hardwire w/pics