I think I'd rather hire an exterminator than have a new roof put on the house....after I'd fattened up Sidney Squirrel.
I read this about mothballs:
Will they keep squirrels away?
(Sigh.) No. If it did it would be all I would ever use. Mothballs are for moths. And they don't even work that well for moths. Neither will loud rock music, basil, mint, garlic, marigolds, ammonia, bleach, borax or boric acid, and catnip. Also forget fox, cat, wolf, coyote, bear, dinosaur or human urine. There is also no device, electronic, magnetic, sonic, stroboscopic, or any combination of these, that will consistently deter these critters.