This document discusses different types of wiring systems used in buildings, including their advantages and disadvantages. It describes cleat wiring, which is the cheapest but only suitable for temporary use. Wooden casing and capping wiring provides better protection but is not suitable for damp places. CTS and TRS wiring uses rubber-sheathed cable and offers longer life though installation requires more skill. Metal-sheathed wiring provides best protection against dampness and chemicals but is more expensive. Conduit wiring, though costly, is best for buildings as it offers maximum safety against fire and mechanical damage.