Not a good person, but vince mcmahon started commentating in 1971, and showing up periodically since then.

Google said William Roache was Ken Barlow In Coronation Street from 1960 – Present, so 22 years longer than vanna, but as an acted role.

She is kind of a presenter. Google said the longest career as a TV presenter is 67 years 151 days, achieved by Sir David Attenborough (UK) between 2 September 1953 and 31 January 2021. So he stopped last year, but still a ton of years.

But she is way up there. Even Trebek only hosted jeopardy for 37 years. Starting in 1984 when vanna was already on the air 2 years, since 1982. Crazy.