Bake cupcakes per box directions and cool completely.
Melt the candy melts with the shortening for 25 seconds, stir, and reheat if necessary.
Place a large marshmallow in the center of each cupcake and spoon 1-2 Tablespoons of the candy melts over top.
Use the back of a spoon to help the candy melts move if needed.
Repeat with the other ghost cupcakes.
After each ghost has dried for about 5 minutes, attempt to attach the eyes - if the candy melts are still too soft, give it another couple minutes before re-attempting.