You may also wish to make a sign that says "I am the light of the world" top help students focus on the theme of the object lesson.
Bring in several sources or pictures of sources of light. Have students identify the purpose of each.
Next, have students identify how Christ functions in a similar capacity.
Here are some examples:
Sun: Is the source of life for all things living on earth. (Christ provides resurrection/life for all men.)
Porch light: Serves as a beacon to help us find home. (Through Christ's atonement, we can live with Heavenly Father again)
Campfire/fireplace: Provides warmth and comfort (When we pray we can feel peace)
Lighthouse: Protects from dangers Flashlight: Defines a safe path. (Perfect example)
Nightlight: Banishes darkness and eliminates fear (Gives knowledge--you can't have fear if you have knowledge)
Match with candles: Light can be shared or given to others
Car headlights: Let us know where we are heading
Lights on the floor in an airplane or movie theater: A guide that can be followed
Have students continue to add to the list and see if they can add to the analogy.