Frister Rosman cub 4 sewing machine?

Yes. As ever Guggle is your friend. It led me to this:

https://howtomendit.com/answers?id=205818

There's a capacitor inside the foot controller which has likely failed.its only there to suppress radio interference and isn't strictly necessary for the machine to function.

More info here

https://www.diynot.com/diy/threads/capacitor-for-a-sewing-machine.296736/

There's a wealth of shapes and styles so I can't be more specific about what to look for. Find a techie chum and ask him/her to look

Wjehdvdg
January 2022