The inverse square law says no [0]. Even relatively high powered transmitters aren't detectable for an Arecibo-class antenna more than a few AU from Earth. If you want a signal detected light years away you need it to be highly directional. An isotropic radiator emitting enough power to be detected light years away is called a star.

So any SETI signals we might detect would almost certainly need to be intentional. That doesn't mean they would need to be responses to something we've broadcast just the sender was aiming their transmitter towards the solar system and sent a signal.

[0] https://web.archive.org/web/20140719094337/http://www.comput...