I am looking for a pen friend of mine I had met in 1982
Väestorekisterikeskus (Population Registry Centre) can possibly help you in locating your friend. The contact information can be found here https://dvv.fi/en/article/-/asset_publisher/osoitepalvelu-sisalto
Contact information, https://dvv.fi/en/contact
Is there a search engine to look up someone's address in Finland?