Unique variable for gameobject with script, not the script overall.

Yes, confusing question i know but i wanna know if there is a possible solution to this:

 void ShipState()
     {
         switch(stateCount)
         {
             default:
                 mousePos = new Vector3(mousePos.x, mousePos.y, 9);
                 transform.position = Camera.main.ScreenToWorldPoint(mousePos);
                 gameObject.GetComponent<BoxCollider>().enabled = false;
                 break;
             case 1:
                 transform.position = new Vector3(Mathf.Round(currentPos.x),
                     Mathf.Round(currentPos.y), Mathf.Round(currentPos.z));
                 gameObject.GetComponent<BoxCollider>().enabled = true;
                 break;
         }
     }

I have several gameobjects that i have in my game and each single one carry this script and use this function. It tracks down which state the gameobject is in.

When the switch is default: the object is not yet placed on the gridboard and it will hover my mouse cursor until i decide to drop it off somewhere. In case 1: i have placed the object on the board and it is "active". I can choose to alternate between these states if i want to pick it up again and place it somewhere else etc.

Now, this stateCount int is controlling which state the gameobject is in. Right now all the objects that are active in the scene with this script will all follow once the int is changed. However i only want it to change to the gameobject i choose to affect.

In order to pick up my gameobject i just click it and its in my mousecursor again in stateCount == 0. But if i have more gameobjects active on the board, they will all follow along..

How do i make that the stateCount int variable is unique to the gameobject only, and not all scripts that are indentical.

 void PlaceShip()
     {
         if(Input.GetMouseButtonDown(0))
         {
             Ray ray = Camera.main.ScreenPointToRay(mousePos);
             RaycastHit hit;
             if(Physics.Raycast(ray, out hit))
             {
                 if(hit.collider.tag == "playerTile" && stateCount == 0)
                 {
                     Debug.Log("placement");
                     stateCount++;
                 }
                 else if (hit.collider.tag == "submarine" && stateCount == 1)
                 {
                     Debug.Log("picked");
                     stateCount = 0;
                 }
             }
         }
     }

This is how i place and pick up my gameobjects with just the click of the mousebutton. Right now it only works with one type of object (the submarine) and in the if-statement: once i change back stateCount to 0 all objects with the script will then act on it, but i dont want that: only one!

Thanks.