Writing this message I'd like to ask is there any possibility to make EVS in Finnish libraries for a Turkish MLIS student who is working as a school librarian…

In Finnish libraries, there are only few volunteers, and it’s usually necessary that they can speak Finnish. I don’t know if there have been any EVS volunteers in Finnish libraries, but you are free to try by contacting libraries. Each library has its own volunteering policy, so you should send email those libraries you are interested in. You can find contact information for Finnish libraries at http://www.libraries.fi/en-GB/libraries/.