The answer to 'GFCI outlet sparking' is that a sparking GFCI (Ground Fault Circuit Interrupter) outlet is typically caused by a ground fault in the electrical system. This occurs when current is leaking to ground, creating a hazardous situation that the GFCI is designed to detect and shut off power to prevent electric shock.
Some common causes of GFCI sparking include damaged or faulty wiring, moisture intrusion, or a malfunctioning GFCI device. If the sparking is accompanied by a tripping GFCI, it's important to address the underlying issue promptly. In most cases, this will require the assistance of a licensed electrician to diagnose and repair the problem.