Silver has the greatest electrical conductivity of any metal at room temperature.
At ordinary temperatures, silver conducts electricity better than copper, gold, or aluminium. Its high conductivity results from the way electrons move through the metal's crystal structure. Silver also has the highest thermal conductivity among metals.
Copper is used far more often for household wiring because it is much less expensive and has useful mechanical properties. Silver's cost means it is normally reserved for specialized contacts, high-performance electronics, solar cells, radio-frequency components, and coatings where its performance justifies the expense.
Gold is less electrically conductive than silver and copper, but it resists corrosion and tarnishing extremely well. That makes gold valuable for reliable electrical contacts even though it is not the best conductor. Aluminium is lighter and widely used in overhead power lines, where low weight matters more than maximum conductivity.