What does this clutch switch do?

Years ago I stripped a clutch/brake pedal set out of an early 70s Duster. The clutch safety switch looked nothing like that one. You can go to Brewer's web site to see what they look like.
I don't know if cruise control was ever offered on stick cars, but if it was that switch could have been there to disengage the cruise so the engine wouldn't rev up.