Theory on what actually triggered the condition of Chuck McGill

Everyone loves to debate whether Jimmy or Rebecca caused the electromagnetic hypersensitivity that Chuck suffers from. But what if the real trigger was specifically the career of Rebecca?

The reason he cannot tolerate electronics around him is rooted in her work. Because of her constant traveling and the phone calls she had to receive Rebecca and Chuck grew apart. The electronics represent the exact tools that took her away from him - we can see this explicitily in the flashback at the beginning of Episode 5 of Season 3.

It is a physical reaction to a mental condition. He internalizes the painful loss of his marriage and projects that psychological trauma onto the devices that facilitated their separation.