The answer to 'why is my surge protector sparking' is that the surge protector has likely reached the end of its lifespan and needs to be replaced. Surge protectors are designed to absorb and dissipate excess electrical energy during power spikes, but over time they can become damaged or wear out, causing them to spark or fail entirely.
Some common causes of a sparking surge protector include overloading the device, using an incompatible or low-quality surge protector, or exposure to repeated power surges. Symptoms may include the surge protector making a buzzing or crackling sound, emitting smoke or sparks, or no longer providing protection against power surges.