Help with GuiText flickering code.

Hello, I am trying to have my 3D Text in my game flicker. I have a script that has my lights flicker and I tried modifying it to fit the 3DText and it keeps coming up with the error: “NullReferenceException: Object reference not set to an instance of an object”
Here is my code

var GuiText1 : GameObject; 

function Update () 
    {
        if ( Random.value > 0.9 ) //a random chance
        {
           if ( GuiText1.Renderer.enabled == true ) //if the light is on...
           {
             GuiText1.Renderer.enabled = false; //turn it off
           }
           else
           {
             GuiText1.Renderer.enabled = true; //turn it on
           }
        }
    }

It’s “renderer”, not “Renderer”. Variables are never uppercase.