I suggest: a Ferrite Bead Choke around each of your A.C. (Hot & Neutral) lines, between, where they enter your panel and before they connect to the controller board. The ones like the first picture, as close to the size of the wire as possible and still easy to snap closed. I'm sure you know, but for others that might read this: make sure you have a good ground on your A.C. supply line. Keep Fluorescent lights as far away from anything that uses Digital Communications. If you have L.E.D. lighting, those emit the least noise. If they run from A.C. power, you might not need put one of them choke things on that line, but they are inexpensive, couldn't hurt. Be sure to make a separation in the A.C. wire and a Ferrite Choke on each line.
The 3D process, (heating, moving, cooling,) makes static. Static wreaks havoc around C.N.C. controls. After all, a 3D Printer, IS a C.N.C Machine.
Anyone having a static electricity problem, (any shock you can feel) in your printing area: Add some kind of ground to either the "hot bed" or the "hot end" so that any static goes to ground thru that instead of through the bearings or rollers or back to the controller.