I have a door going into a bunkhouse that is not visible from where the slide control switches are. On my first day of ownership, I neglected to close that door (it opens IN to the bunkhouse) Natural...
For future reference, I did something similar on our brick/mortar house to turn the light on in the kitchen pantry when the door is open. I just used a momentary push switch --- power is off when the switch is pushed (door closed) and on when the door is open.
That would have worked for your application as well, and could have been put in series. I suspect you were able to hide yours better than I hid mine.