I just (first time) received a letter from "Serafe" the envelope didn't have a stamp on it so I'm not sure it's a legit letter.

I did google translate and a line or two translate to:
<<
totally in favor of public service in the field of electronic media

Swiss collection agency for radio and television
>>

it's a bill for ~213 chf

Can anyone shed some light on this for me - do I need to pay it? Who's it for?

Thanks for the help. Doing additional research now.