Electromagnetic waves propagate through Plasmas?

"The electromagnetic spectrum, or EM spectrum, is the name given to the collection of all electromagnetic radiation in the universe. This is a type of energy that pervades the cosmos in the form of electric and magnetic waves, allowing for the transfer of energy and information."
https://www.space.com/what-is-the-electromagnetic-spectrum

"99.9 percent of the Universe is made up of plasma," says Dr. Dennis Gallagher, a plasma physicist at NASA's Marshall Space Flight Center. "Very little material in space is made of rock like the Earth."
https://science.nasa.gov/science-news/science-at-nasa/1999/ast07sep99_1/

"Plasma react very strongly to electromagnetic forces, and is the dominant force in many cosmic plasmas, e.g. stellar surfaces, active galactic nuclei, and, interplanetary, interstellar and intergalactic space"

"Space plasma moving through a magnetic field generates its own electric current, can act as a unipolar inductor, and it conducts electricity better than metals, e.g. the heliospheric current sheet above, and Birkeland currents."
https://www.plasma-universe.com/

"The aether exists and it is the medium for propagating light and other longitudinal and transverse (electromagnetic) waves across the universe."
https://energywavetheory.com/explanations/aether/

"the Universe is connected, mainly via electric currents flowing through plasma."
https://thehonestscientist.com/electric-universe/