Ways to insulate the two pins for power cord? (Pictured)

[Madeline12]

While working on replacing the carbon comp resistors in this area of my old tube tv, the material holding these pins stable and separated crumbled. They’re pins that plug into the power cord, and the material used seemed to be similar to the kind used in phenolic PCBs. I’m curious if there’s an alternative that I can use and install to serve the same purpose… I have some 1/8” MDF lying around, but I know with moisture that isn’t the best insulator. Any recommendations?

Pics of the pins and the material that crumbled below: