An electrical insulator is any material where electrical charges internally do not flow freely which makes it hard for electric current to conduct properly. An insulator in electrical wiring in a home will help electrical currents flow freely in a home and prevent fuse blowouts and outages. Some common insulators include rubber or flexible plastic. Other materials include glass or ceramic (often used outdoors) or in high voltage situations, hard plastics and even air. A professional home inspector can evaluate the home’s current wiring and determine whether upgrades or repairs are needed.