How to protect myself from catching boils from an infected family member who is having recurrent boils if he touches and shares everything?

Simple hygiene: If the boils are due to a bacteria like staph or strep, everyone in the house probably already has it on their skin and in body cavities, especially the nose. You can reduce the chance of symptoms yourselves by keeping the bacteria count low: bathe or shower (with soap) at least once daily; frequent hand washing or alcohol gel after contact; and antibiotic treatment of the infected person.