You are right. I think it would have to be malfunctioning. Don’t think a properly working one would burn any thing. I had the feeling from some of the articles that people were under the impression a usual and properly working ones were dangerous because of carbon monoxide. The same risk is true of any electric device. It could burn slowly. Everyone should have a carbon monoxide detector and still vent things properly either way. :)

I don’t think they do that story is just people jumping to conclusions. They can produce toxic fumes, but I don’t know where carbon monoxide would come from.

https://3dprint.com/163470/did-a-3d-printer-just-kill-people/