Stop lights

I´m interested to know the mechanism used by the 2000 Volvo V40 T4 on the stop ligths. Does this mechanism work by a vacumm switch at the booster brakes or is it an electrical device on the brake pedal.
I´ll appreciate any dirctions on this matter.

I´m interested to know the mechanism used by the 2000 Volvo V40 T4 on the stop ligths. Does this mechanism work by a vacumm switch at the booster brakes or is it an electrical device on the brake pedal.
I´ll appreciate any dirctions on this matter. IT IS A ELEC SWITCH UNDER THE KICK PANEL ON THE DRIVER SIDE NEER THE BRAKE PEDAL