WARNING: This page is about a different car, the 2004 Mitsubishi Eclipse. However, it is still accessible from the selected car via links, so may be relevant.
Disconnect the connector.
Check for continuity between the terminals of the switch.
Fig 1: Continuity Table
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Fig 2: Identifying Clutch Pedal Position Switch Terminals