The electric folding mirrors on the JDM cars have the switch you have photographed which has its issues, which I did a “How to” to take it apart replace the bulb and re-solder the connection as they suffer from dry joints.
There is also a control ECU which on inspection of the PCB when mine failed was far to complicated for a simple bear such as myself to even attempt a repair.
So I acquired a used replacement part number MB852142 it is located behind the radio bolted with a M6 bolt (M10 socket) to a crossmember near to the Engine ECU, you can replace it by just removing the radio but it is fiddly and you are working by feel rater the being able to see.
The Mirror ECU is available used on your favorite on line auction site, but do search the part number not “Mirror ECU for Mitsubishi GTO” as sellers always want more for GTO parts and the Mirror ECU is shared across suitable year Mitsubishi vehicles (mine came from a Shogun) Link for my “How To” follows Electric Mirror Switch Bulb Replacement (My How To)
Hope this helps