Trump thought they could put lights inside of people:
https://www.usatoday.com/story/news/fac ... 053177001/
Trump then floated the idea that ultraviolet light could be used in the body as a treatment.
“So, supposing we hit the body with a tremendous — whether it’s ultraviolet or just very powerful light — and, I think you said that that hasn’t been checked, but you’re going to test it,” he said. “And then I said, supposing you brought the light inside the body, which you can do either through the skin or in some other way, and I think you said you’re going to test that, too. It sounds interesting.”
I took the trouble to read the article, and they are referring to UV lights being set up in public spaces to kill the airborne viruses and bacteria that are in the air:
https://www.vox.com/the-highlight/23972 ... ide-far-uv
These advocates imagine a world in which far-UV lamps are set up in most large indoor spaces where people gather, emitting rays that kill airborne viruses and bacteria.