In the episode where Zach hurts his knee and is in the hospital, Lisa's mom tells Zach he's going to have to get surgery. She then tells him to get a good night's sleep and leaves. After she leaves, he pulls a cord that leads to the light and it shuts the lights off. When he first pulled the cord, it was on his right side. After he awakes from his bad dream, the pull cord is then on his other side!