So long as you have a reference to the gameobject or transform (which it sounds like you have with your mouseover functionality), you can simply use GetComponent to get a reference to the component/script you want:

http://unity3d.com/support/documentation/ScriptReference/Component.GetComponent.html

In your camera script, probably have

var boxes : GameObject[]; // assign your boxes in inspector or code

... some function..

  var ms : MyScript = boxes[1].GetComponent("MyScript");
  ms.myBool = false; //or whatever

Note you can pre-fetch the components of those boxes in a Start script so you don't have to GetComponent each time.

This script can called any tag"box" in gameObject script.

// Disable the spring on all HingeJoints 
// in this game object
var boxes : GameObject[];
var boxScript : boxScript;


function Start ()
{
    boxes = GameObject.FindGameObjectsWithTag("box");

    for (var i : int = 0; i < boxes.Length;i++)
    {
        boxScript[i] = boxObject[i].GetComponents("YourScript");
        boxScript[i].yourBoolean = false;`
    }
}