There is a star we've observed between 1400 and 1500 light years away with odd, non-cyclical light fluctuations. It may be indicative of a megastructure being built or falling apart around a star.
Unfortunately, I think a pulsar type situation is much more likely. There's many things that could potentially cause those fluctuations, especially considering our relative lack of knowledge about extrasolar space. In 1967 when we started detecting regular, precise bursts of EMR from deep space it looked a lot like aliens.