But as said, wide area stun failed to stun anybody who wasn't exposed to the open sky from which the stun rays fell.
Indeed, we lack evidence that phaser fire of any
sort could go through walls of any
sort, except of course by blowing a hole in them. This 100% lack of evidence should count for something, even though it of course isn't the same thing as some character declaring that phasers can't go through walls.
FWIW, only DS9 "Field of Fire" ever includes dialogue about walls generally being an obstacle to weapons fire, and it being a big surprise when they are not - but even there, the heroes know from the get-go that they are dealing with a chemically propelled slugthrower rather than any other sort of weapon, so through-the-walls weapons might still theoretically exist.
It's just that there is no positive evidence for them...