I would go to google.com and type in getting rid of skunks in yard. A lot of good answers pop up. I would forget the moth balls they are more of a danger to you and pets than the skunk. Some of the responses are, shoot the skunk, use a trap, place ammonia soaked rags about the property, find the den and fill it in after placing a screen over the top of the den. The night critters are looking for food from either you as a source or grubs in the lawn. Last resort is to hire an exterminator.
My old stand-by sprinkle some moth balls along the edge. There has to be a reason why the skunk is spraying; that is their only line of defense and they use the spray only as a last resort. They hiss, stamp their feet in warning before they spray as they have only a limited amount to use. You have have feral cats coming onto your patio. Is there food there that is attracting both?
There are electronic devices you can buy that emit a sound skunks don't care for and they stay away. Do a search on Gogle or go to Amazon and you can find them. Another option is a dog. A mid to big size dog. You could also just ask at a Lowes or Home Depot and they may have something.
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