Not that I want to be caught agreeing with DarkMatter on anything, but I have both seen and heard of enough black dust on TV/monitor faces. Even dust with the odor of that accumulating in the flyback transformer area. My hypothesis is greasy/stick/tarry particles, maybe with a thin coating of soot or other fine carbon particles.
And conductive particles can have a net charge as well as nonconductive ones. My suspicion is that some sort of black dust particle, probably mostly made of some sort of grease or tar, has a tendency to be charged one way or another and be attracted to TVs, monitors, etc.
- Don Klipstein ( snipped-for-privacy@misty.com)