'93 940 Brake light switch

[flash3b]

I'm trying to diagnose a no brake light problem on my neighbor's 1993 940 sedan.

When I drop the kick panel, all I see touching the brake pedal arm is a switch with a vacuum hose & a pair of wires connected to it. (The wires connect to the switch with a small white double connector.) The switch sticks out horizontally towards the driver's knees. It seems to me that this is the cruise control switch, 3/38 on the Volvo wiring diagram I have. Where would I find the brake light switch? Or could the c/c switch also operate the brake lights on some cars?

I know I should also check the bulb failure sensor, but that looks pretty tough to check other than by replacing it.

P. S. Whenever I have to work underneath the dash, I wish I were a 2-foot tall monkey!