It occurs due to following reasons-
A short circuit occurs when current bypasses the appliance via a channel with little or no resistance, such as when frayed insulation exposes a wire and allows it to touch the appliance's frame, allowing the current to travel directly to the ground.
if the insulation of the wires used in the circuit is destroyed, resulting in direct contact between the live and neutral wires. As a result, the circuit's current increases.
When old wires with low current capacity are used for high current equipment, there is a risk of overheating, which can result in a short circuit.
A faulty plug, a faulty power cord, or a malfunction in the device might cause a short circuit.