What type of electrical insulation is most commonly used in residential wiring?

PVC (Polyvinyl Chloride) is the most commonly used type of electrical insulation in residential wiring due to its excellent electrical properties, durability, and resistance to moisture, chemicals, and abrasion. This makes it highly suitable for protecting wires in various environmental conditions typically found in homes. PVC insulation is also cost-effective and can be easily manufactured to different thicknesses, allowing for flexibility in application across various electrical systems.

In contrast, while rubber insulation does provide good protective qualities, it is less common for residential wiring due to higher costs and specific application requirements. Duct tape, although useful for temporary repairs, is not an appropriate or safe choice for electrical insulation, as it does not offer the necessary electrical resistance or durability. Fiberglass insulation, primarily used for thermal insulation in buildings, does not have the electrical insulating properties needed for wiring. Therefore, PVC stands out as the preferred choice for ensuring safety and efficiency in residential electrical installations.