Oddly enough that could be environmental.
In brief there could be some kind of electrical (or electromagnetic) signal that is interfering with the circuits in your Mac. It is not uncommon but usually manifests itself in something that happens all the time or only when a train (or whatever) goes by.
If it is indeed environmental (and there is no guarantee that it is) then often just re-orienting the laptop (tilt the screen at a different angle, turn the computer to face another direction, etc.) might help. Failing that moving it to another room or another location in the room that it is in.
As it is a laptop, take it outside, like to a park, far away from electrical lines and see if the issue repeats. Or try your favorite coffee shop with wifi.
If you can do any of this while the static is happening, even better as you will get immediate feedback.
Failing all of that it may be time for a visit to an Apple Genius to have them diagnose the hardware.