Can't add script: The script is an editor script

Hi, i want to draw all the BoxColliders in the Scene while i’m creating it, so i created the script below to draw a box using the Gizmos utility.

using UnityEngine;

[ExecuteInEditMode]
public class ShowCollider : MonoBehaviour
{

    // The Collider itself
    private BoxCollider _collider;

    void Start()
    {
        _collider = GetComponent<BoxCollider>();
    }

    void OnDrawGizmos()
    {
        Gizmos.color = Color.blue;
        Gizmos.DrawCube(_collider.center,_collider.size);
    }

}

The problem is that i can’t add this script to any object because it is an “editor script”. I’m a bit confused on how should i use an “editor script” because from the documentation it looks like you can add an “editor scripts” to gameobjects, there is a manual entry here where they add an “editor script” to an object to keep it oriented towards a certain direction.

My script is in the ./Asset/Editor folder.

So what am i doing wrong?
My guess is that there is something wrong with the OnDrawGizmos function.

My script is in the ./Asset/Editor folder

That’s where you’re going wrong… put it in assets/scripts instead (or, in fact anywhere other than /editor) and it will no longer be an editor script.

Problem fixed here : Can't add script because it is an editor script Unity - YouTube