It sounds like it might be Pica

http://www.vmth.ucdavis.edu/home/beh/feline_behavior/pica.html

What is Pica?

Pica is the act of eating non-food items. In less serious cases, cats may chew or suck on objects, but not actually swallow them. Common targets include yarn or string, fabric, wool, phone or electric cords, and plants. Any object may be a potential target, however.

Why is Pica Dangerous?

Other than its destructive potential, pica can be extremely hazardous to your cat's health if non-food items are consumed. Ingested fabric, string, or other materials can lodge in your cat's stomach or intestine. The blockage prevents the passage of food and may cut off the blood supply to these organs. Both are life-threatening conditions. Cat's that chew on power cords may be electrocuted. Additionally, many common houseplants are toxic to cats; chewing or eating these plants can cause a wide range of symptoms from drooling to death. If your cat has a history of ingesting non-food items and becomes lethargic, vomits, or displays other concerning behavior, take them to your veterinarian immediately.

Why Does My Cat Eat/Chew on Non-food Items?

No one knows exactly why some cats exhibit pica behavior. Because pica has been associated with a variety of diseases including feline leukemia and feline immunodeficiency virus, a veterinarian should examine any cat with pica. A genetic component is also suspected since wool or fabric sucking/chewing is more commonly found in Oriental breeds such as Siamese cats. Although it is normal for cats to eat small amounts of grass, consumption of large amounts of plant material may be an indication of a dietary deficiency or illness. Once medical causes are ruled out, behavioral reasons for pica can include boredom, attention-seeking, attractive odors, hunger, and learned behavior.

Treatment:

To rule out medical causes, a veterinarian should examine all cats displaying pica. Once your veterinarian gives your cat a clean bill of health, discuss with them what steps you can take to modify your cat's behavior. These may include the following:

1. Remove targeted items - Placing clothing, blankets, houseplants and electric cords out of the reach of your cat is often the easiest solution. Storage containers, electric cord guards, and other useful items are available at most home supply stores.

2. Provide alternative items to chew or eat - Food-dispensing toys, durable cat toys, or pieces of rawhide can be used to redirect your cat's chewing behavior to more appropriate and safe items (see handout). For cats attracted to houseplants, small flowerpots of grass or catnip can be planted and kept indoors. Birdfeed can be used as a safe source of plant seed.

3. Provide lots of structured play - Many cats chew on household items out of boredom. Provide interactive toys and set aside time each day to play with your cat.

4. Increase dietary fiber - It may help to increase the amount of fiber in your cat's diet. Besides providing more dietary fiber, high fiber foods usually contain fewer calories. Your cat may be able to satisfy their craving to eat more while still maintaining their weight. Consult with your veterinarian before making any changes to your cat's diet.

5. Make targeted items aversive - Occasionally, applying aversive substances (e.g. hot sauce, Bitter Apple®, Bandguard®) to an item may deter a cat from chewing it. If this is not possible, spraying strong smelling substances (e.g. citrus air freshener, potpourri) or using physical deterrents (e.g. upside down carpet runner, Ssscat®, Snappy Trainers®) around an object may prevent cats from approaching.

6. Consult with a veterinary behaviorist - If your cat continues to ingest non-food items, referral to a veterinary behaviorist is recommended. Further environmental and behavior modification plans, specifically tailored to your pet, may be needed. In some cases, medication may be helpful.