Enableing & disabling a script on anouther object

hello im having a bit of trouble disabling a script that allows the players gun to follow the cursor this need’s to be disabled when the game is paused i have the pause script but the problem i have now is how to disable the component on an entirely different object i either get object to set to a reference of a gameobject or GunMover(which is the name of the separate object)does not exist in the current context context heres my script maybe you can see whats gone wrong here.

using UnityEngine;
using System.Collections;

public class Pause_Menu : MonoBehaviour {

	public bool paused = false;

	public float lockgun;

	void Start ()			    
	{
		foreach (Transform child in this.transform)
			child.gameObject.SetActive(false);		 

		lockgun = GunMover.GetComponent<follow_crosshairs>();
	
	}
	
	// Update is called once per frame
	void Update ()
	{
			
		if (Input.GetKeyDown(KeyCode.Escape)) 
		{ if (paused == false)

		  	pauseon ();
			
		else if
			(paused == true)
	        
			resume ();

		
	     }
	}
void pauseon ()
	{
		foreach (Transform child in this.transform)
		child.gameObject.SetActive(true);
		Time.timeScale = 0;
		paused = true;

	}
void resume ()
	{
		foreach (Transform child in this.transform)
			child.gameObject.SetActive(false);
		Time.timeScale = 1;
		paused = false;
	
    }
}

Any help would be much appreciated

Thanks

If “GunMover” is the name of the game object with the ‘follow_crosshairs’ script, then you want:

 lockgun = GameObject.Find("GunMover").GetComponent<follow_crosshairs>();