Poor Behavior Habits - Chewing
If your loved one has developed a habit of repetitively chewing on things, get them checked by a dentist in case something is going on with their gums our mouth.
The most important and obvious is to simplify and make safe the environment as much as possible to remove chew hazards.
Try substituting something that they can chew on our suck. You may even try some product for babies or infants like a pa iffier or teething blanket.