Electric guitars and their equipment are known for producing feedback, hum, buzz and other undesirable forms of static-like noise. Depending on a room or engineer's setup, there are several things you can do to provide proper grounding to your equipment and reduce or eliminate these rather simple problems. However, the biggest problem guitarists and engineers have is locating the actual cause of the static, as there many noise-producing issues that may appear to be grounding issues when grounding really has nothing to with why your pedal is making so much noise.
Locating the Problem
Eliminate the possibility of your static being caused by something else, such as a bad amp, old cable or loose guitar connection. Musicians often overlook the possibility of several causes and jump straight to the first conclusion that comes to mind.
Test your pedal by using it in a different amplifier or speaker with a different guitar. Even though you may not hear static while the pedal is in bypass in your original setup, activating the pedal may not be the cause of the static; it may simply amplify what you could not hear before.
Turn off or unplug any TVs, neon lights or other electronic sources that emit radio waves. Shut down cell phones, as these phones are specifically known to interfere with musical equipment.
Stand as far away from amps, monitors, pedals and other instrumentalists as possible.
Check the pedal itself to make sure it does not have loose wires or joints. Plug in and unplug your quarter-inch cables several times, and twist them back and forth to loosen any rust that may have built up.
Grounding the Pedal
Plug the pedal into a direct box, especially if you are running your guitar and pedals directly into a mixer or interface; in other words, you are not plugging into an amplifier, which may also be mic'ed. Direct boxes can still be used for amps as well.
Reduce the use of patch bay power-chains to a single daisy chain of pedals. Plugging pedals that go to multiple amps all into the same power supply can cause your groundings to cross and begin to hum.
Purchase isolated transformers, or power supplies, for your pedals. Because grounding issues arise in the main power sources, plug these into their own outlets. You can also use power strips with "EMI" filtering as well, since many outlets simply produce a lot of noise.
Upgrade your pedals. Many cheap models are only low in price because, while they may sound great for your style of music, the physical hardware is low quality and prone to problems. Some lower models of amplifiers and guitars may cause issues with high-quality pedals as well. The better the quality of your overall setup of equipment, the easier it will be to properly ground your pedals.
Place cables, such as power supplies and quarter-inch cables, as far away from each other and your pedals as possible.
Take broken or damaged equipment to a professional to have it repaired and prepared to properly be grounded.