Stop/Brake light switch located

Where is the Stop/Brake light switch located on the Mercedes C320 2004? Does my car not have one? I took my break pedal and dash out and still couldn't find it. How can I replace it if it doesn't exist? Please help!

ESP/BAS/ABS visit workshop light came on. Mercedes C320 4matic 2004. Sometimes I can't shift my car from park to drive but the engine starts. Sometimes when I am able to shift to drive the car stays at one gear and doesn't accelerate to the next. I was told to change the Stop/Break light sensor. When I disassemble my break pedal and the dash underneath, there was no switch on my car at all.

I look all over under where the pedal area was at and still couldn't locate the switch. If my car doesn't need a switch why would they tell me it's the switch and knew that my car doesn't have one. If there is a switch, where is it located in the car? Please help. Thanks in advance.