From the submitter:
"The rubber button fell off my bike's rear light, and the actual switch was far in the case so I needed something thin to reach it. Turns out a pin fixed with scotch-tape is almost perfect. Paper is for improved length adjustment and better stability of position."
"Dry here to open?" So it's some kind of moisture-activated locking mechanism, where dehydration makes said mechanism weigh less and rise, thereby releasing the lock and opening the door?
Unless... oh wait, I see what it says now. Never mind, carry on.