@Amadeus
This actually works! : )
https://streamable.com/hpzy3
I got 2 sliding doors, about the same size of the grill light, with spawnarg "translate_speed" set to 2000 (so fast it looks like it doesn't move), one with spawnarg "open" set to 0, the other one set to 1, and trigger them both with the same switch. Have 2 of these grill lights, one green and one red and bind the green to a sliding door, and the red to the other, .. one of them is always "hidden" in the wall, and the other visable.
Spawnarg "translate" set to 20, on x,y or z, depending on the orientation, seems enough to hide the model, and you can use the first suggestion I did to light up the surroundings with a seperate red and green light.
I used this model: models/darkmod/lights/non-extinguishable/grill_light_short.lwo