GetConponent

gistfile1.cs

using UnityEngine;
using System.Collections;

public class Test : MonoBehaviour
{
	void Awake ()
	{
		gameObject.active = false;
	}

	public void Call ()
	{
		
		Debug.Log ("Call");
	}
}

//別のオブジェクトに付加

using UnityEngine;
using System.Collections;

public class NewBehaviourScript : MonoBehaviour
{
	public GameObject g;

	void Start ()
	{
		g.active = false;
		Debug.Log ("Tes");
		g.GetComponent<Test> ().Call ();
	}
}