The safety cupboard is the eponymous opening in the wall enclosed with mobile wooden door and is located in Salad Fingers' house. It is featured in the eighth episode named Cupboard. Salad Fingers feels safe there, occasionally playing.
In the episode, he hides in the cupboard from his radio, who was unable to find a station and was sending hideous sounds. In the cupboard, he was playing with his fingers and impersonated Penny Pigtails, who went to the market. He also found a piece of brown hair there to complete his hair quintette.
Later in the episode, he went in there crying after he ate the hair quintette.