Secret Level 1 - what does this switch do?

I have used the DLE-XP Level Editor to find out what this trigger does, and it does indeed have a purpose:

This screenshot isn't totally clear because the editor is so dated, but essentially that trigger (in red and yellow) temporarily opens a door down the hallway from it (marked in green), in the opposite direction. I wouldn't recommend using the editor too much if you get stuck, only because it slightly ruins the experience, especially in the secret levels when triggers and puzzles are numerous. However, I did want to check, because there are a few useless triggers that slipped through QA :)