The space fillers in the box are also not vapour or water proof. the back box can allow water in via the hub where the emt and connector screw into the box.
If not located in a hazardous location a small hole big enoug to let water out and ants in can work for condensation.
Drilling holes in glass is a bugbear and don't bother if the glass is tempered. it will just break if you drill.
