Replacement water shut off valve stem is too short to protrude past the wall board
Make the drywall hole a lot bigger or just big enough for your hand to operate the valve &amp; put one of these Access Panels (left) over the drywall hole. Preferably glued or caulked &amp; drywall anchor screwed, since you need to pry these open with a flathead screwdriver. Or, 1 or 2 (hot &amp; cold) of these 2-gang electrical outlet covers (right). These just need 2 screws in the drywall at opposing corners to then just slide up &amp; off...a shot of spray paint to camouflage.