The only one of the 3 main subscription websites that has any census and voter lists for Finland is
My Heritage
Finland Church Census and Pre-Confirmation Books, 1657-1915
But, census records are available for Finland from free sites
FamilySearch
No census and voter lists come up in the All Published Record Collections, but when searching in the FamilySearch catalogue, I only found 1 collection, in the Finland Census category, that had digital images
Uudempi tilikirjakokoelma : läänintilit, 1635-1809
The Family Search Wiki shows that there is a collection that is scheduled to become available on FamilySearch:
Finland, Census, 1734-1860
Finnish National Archives
Henkikirjat (Census Records), Finnish National Archives, 1634-100 years ago
The FamilySearch Wiki – Finland Online Genealogy Records page has a section on how to use this collection
Background of featured image is a photo from Unsplash – https://unsplash.com/search/finland?photo=XrwVIFy6rTw Photo by Vincent Guth
