"Static" is sometimes used, informally, to describe any noise, click, pop, crunch, crackle or snap that is unwanted and electrical in nature. While static electricity discharges can make sounds like this, a persistent noise probably has another origin. There are many ways for such noise to affect an audio signal, from faulty equipment, to system settings and noise induced from other devices, so systematic trouble-shooting is the best approach to identify and remove unwanted audio artifacts.
Troubleshooting for Noise
Re-seat your audio connections by unplugging and reconnecting any detachable cables or connectors. Oxides can build on metal connectors, causing poor connections and, possibly, noise. Re-seating can help avoid oxide build-up.
Move cables and connectors gently, to see if this movement causes the noise you're hearing. Wires inside cable may become frayed, causing intermittent cut-outs that cause noise. Solder connections on connectors can fail as well, causing similar problems until the connect fails completely, and no sound is heard. Replace or repair faulty cables or connectors.
Check your signal levels to see if noise is coming from distortion. Both microphones and the amplifiers to which you connect them can cause noise if audio is too loud. Digital distortion occurs as clicks and pops, while analog distortion is often described as fuzzy-sounding. Move the microphone away from your voice or sound source, or reduce the input level of the device into which your mic is connected until clear sound with no noise is achieved.
Consider the type of microphone you are using, since the mic technology may have a bearing on where noise originates. For example, headset and lavalier mics are both subject to handling and contact noise. Hair, clothing and movement can cause unwanted sound, and a mic brushing against fabric often sounds like static.
Set up a wireless microphone carefully to ensure best reception and lowest noise. wireless signals are vulnerable to interference from electrical equipment and other radio signals, so set up the receiver within line-of-sight with the microphone. When possible, use the balanced XLR connection from the receiver, rather than the unbalanced phone plug.
While most static-type noise occurs from sound source and amplifiers, your speaker connections and speaker condition can also cause electrical noise.
Do not attempt to open or repair any electrical equipment with which you are not familiar. Some devices such as amplifiers may present serious shock hazards.