There isn't a single external switch you can point to. The switch is a component *within* the clutch pedal mechanism. To access it, you'd need to remove the clutch pedal assembly. This is a more involved process requiring mechanical knowledge and tools.
If you're troubleshooting starting issues related to the clutch, it's best to consult a Corvette-specific repair manual or a qualified mechanic. Trying to locate and replace this integrated switch without the proper knowledge could lead to further damage.