Our bathroom is a bit small and I want to take advantage of all the space I can for making shelves. I would like to remove the drywall on the bathroom side of an interior wall between 2 studs and use thin pallet wood to frame in a shelf that will protrude out from the wall a bit. Are there any rules or restrictions when doing this? This is on an interior wall. The other side of the wall is a bedroom closet.
Edit to add details
The shelves will start 18" from the edge of the shower, but they will be about 3.5' off the floor and will be replacing drywall (although it may be the green mold resistant stuff). I'm going to trim the back and sides with some thinner gauge pallet wood, and the shelves themselves will be made from thicker pallet slats. Behind the pallet wood, the studs and drywall will be painted dark brown. I'm thinking I will need to fill the cracks/nail holes in the wood to keep water out. White caulk would look interesting in the weathered wood. Will a full moisture barrier be needed behind the trim? Or can I just fill the cracks as suggested?