What type of wire should be avoided in outdoor lamp holder connections to prevent insulation damage?

In outdoor lamp holder connections, insulated wire is recommended because it provides a protective layer that helps to prevent moisture and environmental factors from damaging the wire's conductive core. While insulated wire is crucial for safety and longevity in outdoor applications, non-insulated wire is particularly risky in this context, as it lacks that protective layer and can degrade when exposed to the elements. Stranded wire, while flexible and useful in certain applications, can also be subject to insulation damage if not properly secured and protected in outdoor settings. Therefore, avoiding insulation damage necessitates the need for insulated wire to ensure the longevity and safety of the outdoor electrical installation.