SOExampleBehaviour v2

SOExampleBehaviour2.cs

using UnityEngine;
using System.Collections;
[ExecuteInEditMode]
public class SOExampleBehaviour : MonoBehaviour
{
    public SOExample test;
    public void OnEnable()
    {
    	// find existing instance if needed
         if (test == null)
            test = Object.FindObjectOfType<SOExample>();      
	// then instantiate if needed
        if (test == null)
            test = ScriptableObject.CreateInstance<SOExample>();
    }
}