Brake light switches are connected to your vehicle’s brake pedal. They’re what cause your brake lights to go on when you’re slowing down or stopping. You are legally required to have properly working brake lights. They are a critical safety feature of your vehicle because they warn motorists behind you that they need to slow down so they won’t hit you and cause a rear-end collision that could be dangerous for both vehicles’ occupants. The electrical wires on brake light switches can wear out over time and eventually break. If that happens, not only will your brake lights not work properly, it can also affect the operation of the shift interlock system and not let you shift from Park to Drive.