Originally Posted by
grant15clone
I would not recommend putting cardboard in there as a replacement as it is flammable. The old plugs had a piece of asbestos that looked like thin cardboard there but often is lost along the way. I would recommend new replacement plug ends that are non polarized that you can get at a hardware store that are easy to install and are much, much safer.
~G~
That is what we do - you can buy the whole unit from sew-classic and other places