When a cat feels threatened, they often urinate outside the litter box and scratch things in order to feel better. Nicole F. writes:
It sounds like Ghost is feeling insecure. That can be difficult when a cat is as smart as Ghost is. He's going to find a way to make himself feel better, even if that means getting outside. He will also feel better if he spreads his scent around by urinating and scratching improper areas.
It's important to remember that cats don't act out of spite, ever. They simply don't have the capacity for that. It can be easy to interpret their behaviors that way because we're so used to looking at them as if they were small humans. They aren't, so the first step is to try and imagine the situation from Ghost's point of view. He's clearly agitated, so what's upsetting him?
Many times, there's a less visible aggressor in a multi-cat household and Ghost may be getting bullied. He may even feel bullied by you. You should never, ever shout at or push a cat off of anything. That's physical aggression in cat terms and most cats will respond negatively to it, just as Ghost has. When you get physical with him in any way, especially when you're upset, he will see you as a predator. All he will learn from those interactions is to fear you. He will not connect your aggressive responses to his own behavior. Cats do not have a pack mentality. They look upon us as equals, not as masters to be obeyed.
It will help if you offer more positive reinforcement. Instead of chastising him when he does something you don't like, treat him when he's behaving. When he uses the litter box appropriately, offer him a small treat. When he lounges in a spot you like him in, offer him a small treat. If he does something you don't like, overwhelm him with love and gently move him away. He may not enjoy being handled in this way, but he won't see it as aggressive, especially if you do it in a happy way. Be consistent in this behavior and you'll see change.
Think about altering your own behavior toward Ghost. You obviously care about him enough to reach out to us. Just take some time to consider how you might make him feel more secure. It will take time, but he will respond to your efforts.
There are even more good ideas in this previous post about helping a shy cat feel more secure: http://kittyhelpdesk.com/help-desk/helping-your-cat-feel-secure
Best wishes to you and Ghost!