How to Stop Your Cat From Chewing Electrical Cords

Stress
Stress can prompt a wide range of odd behaviors. In these cases the chewing serves to relieve anxiety and simply makes the cat feel better emotionally 8
How to Stop Chewing
Take your cat to the veterinarian for a checkup if it displays inappropriate chewing behavior so that any underlying health or behavioral problems can be discovered and addressed. In the meantime take steps to keep your cat safe.
Cover electrical cords by running them through PVC pipes or by taping them down with electrical tape. Anything that can keep them from seeming to move about on their own can be really helpful in keeping your cat from being interested in them at all. 

Use a motion activated humane kitty deterrent. There are several on the market that can spray a light puff of air hiss or make other noises to send your cat in
another direction.
Offer the cat alternatives to chew such as cardboard or cat approved dental treats. There are several that are approved by the Veterinary Oral Health Council that can help prevent tartar and help your cat get some appropriate chewing done.
Add digestible fiber to your cats diet which prompts some cats to reduce their chewing activity or even stop altogether 9 Fresh cat greens green beans or lettuce added to the cats food bowl may do the trick. Some of the hairball formula commercial diets may also work as they provide increased fiber as well.

Reduce anxiety to help eliminate the
need for chewing. Consider trying a synthetic kitty facial pheromone to relieve stress and soothe your cat 10 Otherwise make sure your cats litter box is spotless and that it has enough toys and playtime with you to stave off boredom.