Interface knows it's attached to a MonoBehaviour?

Unity Engine
1

How can I make the interface know that it’s only attached to scripts that are inheriting from MonoBehaviour?

Because of that I can’t load from the Resources folder the gameObjects with the interface I want.

ISpell Spell = Resources.Load<ISpell>("Spells/" + StolenSpellPath);
2

Assuming you’re doing this

public class MyClass : MonoBehaviour,ISpell
{
    // blah
}

You can Load as a MonoBehaviour and then cast to ISpell.

var obj = Resources.Load<MonoBehaviour>(path);
var spell = obj as ISpell;