write-in vs campaigner

write-in and campaigner both are nouns.

Word	Noun	Adjective	Verb	Adverb
write-in	Yes	No	No	No
campaigner	Yes	No	No	No

As nouns, campaigner is a hypernym of write-in; that is, campaigner is a word with a broader meaning than write-in:

write-in: a candidate for public office whose name does not appear on the ballot and so must be written on the ballot by the voters
campaigner: a politician who is running for public office

Other hypernyms of write-in include candidate, nominee.

write-in (noun)	campaigner (noun)
a vote cast by writing in the name of a candidate who is not listed on the ballot	a politician who is running for public office
a candidate for public office whose name does not appear on the ballot and so must be written on the ballot by the voters