During WW2 the German forces used the lighthouse as an observation post. Navy officers decided when the lantern was lit and only did so when their own convoys sailed past.

During the reconstruction work a two-tone electromagnetic foghorn reaching 6 nautical miles was installed and it remained in place until 1985. A radio beacon was installed in 1955 and the light station was connected to the local electric grid the following year. In 2005 Slettnes Lighthouse was one of the last in the country to be automated and has since not had permanent on-site staff.

The light station is owned by the Norwegian Coastal Administration and is managed in collaboration with Gamvik District Council. The light station can now be hired for events, meetings and tourist accommodation, and during the summer season there are guided tours as well as a small cafe.

In 1998 Slettnes Light Station was given protected status in accordance with the Norwegian Cultural Heritage Act.