It really doesn't matter what you call it because I believe that it is acquired from exposure or over exposure to the offending agent, e.G., electromagnetic waves, radio frequency waves. Everyone is different, what harms one person may not cause harm to another. Just like allergies, some people are allergic or develop intolerance to things that may or may not be a problem with another person.
Electrical sensitivity should be classified as a disease because not everyone has it. Maybe it's more of a disorder rather than a disease, because a disease implies it may be transmitted or passed on from one generation to the next. Electrical sensitivity is rare, but as more and more grids get more powerful, humans may become more sensitive to the strong EM fields that surround charged electrons.
Electrical sensitivity should be classified as a disease, because it not something that people can help. Even if it might have a mental component, electrical sensitivity is not something that can go away if people are simply tougher or mentally stronger. Electrical sensitivity needs to be treated as the physical problem that it is.
Any disease probably has a component of mind as well as of body, so both of these could technically be true, but if someone is physically sensitive to electrical activity, then that person definitely has a bodily illness that should be classified as a disease, diagnosed this way, and treated as such.
I have researched things for the neighbor I mentioned and I found all sorts of forums and products that people who claim to have ES use. There were even rocks and crystals people buy for almost $1000 trying to take away electricity. She unplugs everything in the house at night and she said that my cell phone would give her a seizure. I believe it is more of a mental issue where the brain thinks it is suffering effects and an actual physical ailment.
I do not believe electrical sensitivity can be classified as a disease or a psychosis. A disease would mean that there is something inherently wrong with the body and I do not believe that is the case seeing that electricity as we use it is more of a human construct. Psychosis has to do with problems with the mind and I do not believe electrical sensitivity is the product of hallucinations.