Is It Possible to Scan Radio Signals for Signs of Life?

The most distant probe we have ever sent only recently left the solar system. It is a really difficult problem to know how to scan radio signals for signs of life, because we don't know what that life would be like. There are some basic things to look for if you want a message that comes not from earth. We don't even know whether it be a technological civilization. Thit would be cool. I wonder if i cold also send a probe right, like, four light years away. You know, maybe in 50 years we could send something there that reaches there, right? It's possible.