Set the mouse trap and set inside the box on one side.
Place the candy or other object on the other side of the box.
Beforehand explain to someone what you will be doing because they need to be willing to help! They will stand behind the box and place their hand through the curtain. They cannot see what is inside the box (you have told them beforehand, but they do not know what side you placed the objects). Your job is to represent the role of the Holy Ghost and guide them to the candy. You will do this by quiet whispers. The person must listen carefully and think about their actions beforehand or they could get in the mouse trap.
Talk about how the mouse trap represents the traps Satan sets for us and if we are not careful, and follow the promptings of the Holy Ghost, we can easily be caught in one of his traps. But by following the Holy Ghost we will always be led to that which is good and wonderful!
(Be very careful doing this object lesson! You may want to disable the mousetrap by soldering it before beginning, or place it upside down inside the box. You could even use one of the humane mouse traps found here to protect fingers. Just place it so the opening of the mouse trap is toward the back of the box. ~Jenny)