We could barely see evidence of our own existence with current tech from more than a few dozen light years away - and the most obvious evidence for sapient life here that's distantly visible is the radical change in atmospheric composition over the past hundred years or so, which is only visible (with our tech) from locations that lie exactly on our equatorial plane such that Earth passes between those locations and our sun every year.

In terms of radio transmissions, we're struggling to communicate with the Voyager craft and they've only just passed the heliopause…

We'd never detect alien tv/radio transmissions even from the nearest stars, and that's assuming that we're even listening at the right time to catch the narrow high-power transmission window - terrestrial communications have invested hard into more efficient methods as well as widespread encryption, meaning that 1) there's dramatically less RF blasted into space compared to 50 years ago, and 2) what is broadcast is essentially meaningless noise.