Bob I apologize, I sent you on a wild goose chase. The switch is integrated into the BAS solenoid valve at the lower part of the booster and is not serviceable. The switch does operate the brake light relay in the fuse panel next to the booster. All this info and locations are on page 8L-90 in the service manual.
Seems some confusion can come about because of the use of a stop lamp and stop light wording. There is a switch at the top of the brake pedal from what I understand.