In 2015, astronomer Tabeta Boyajian and her colleagues reported that a star at a distance of 1400 light-years from us sometimes dims quite a lot, which initially seemed extremely unusual. One explanation was the assumption that the luminary is surrounded by a Dyson sphere.
The idea, proposed many years ago by physicist Freeman Dyson, is that advanced civilizations may be building giant structures in space consisting of a swarm of solar panels. This helps them to collect enough starlight for the development of technology and life. Such structures can sometimes interfere with the passage of light from the star, causing periodic darkening visible from Earth.