I'm redoing my back landing area and pulled off a piece of trim off the wall and a piece of quarter round off the staircase because I want to sand and paint the wall and don't want random pieces of trim anymore.
Turns out there is nothing behind the trim. Do I need to cut a strip of drywall first or could I fill it in with some sort of plaster? If I need to cut a strip of drywall how would I screw it down then? The wood visible inside this strip of wall is the hardwood in the room next door, I don't really want to screw into there.