This is getting some press: unusual fluctuations of radiation from the distant star KIC 8462852 are consistent with what might be seen from a Dyson Sphere, a hypothetical structure of the type that might be built by an alien Type 2 Civilization. Read about it in Universe Today. Have we discovered evidence of extra-terrestrial construction? The actual likelihood seems vanishingly remote... but still, awesome. KIC 8462852 is over 1,400 light years away, meaning that communication would require time spans greater than the duration of most human civilizations, much less human lifespan.
It's interesting to speculate what kind of changes we might see in humanity if we ended up with compelling, yet arguable evidence that we were not the only intelligent life in the universe. Particularly if we find ourselves out of communication range. Not alone... yet, inevitably, still alone.