How does the parenting drill down system work?

Hey guys, I have this prefab that is made up of three mesh pieces. A Light, a Pole, and a Base. They are setup in the following fashion:

-Base
-Pole
-Light
-Light Component

I want the light component to dim over time, but i want the script to be kept inside Base. How do I pull the light component into a variable in a script on Base so that I can edit aspects of light from there?

Not sure why but the post lost my formatting…

-Base
   -Pole
      -Light
         -Light Component

draft - not tested, keywords not checked for accuracy:

var light : GameObject;

function update()
{
light.intensity =  Mathf.PingPong(Time.time, 3);
}

Put this on your ‘base’ and the ‘light’ variable will appear under it’s properties in the unity editor gui - simply drag the light you want over to it.