Even the focus on on radio is potentially misguided. Perhaps there are alien species who's home planet is under some heavy fog so they have evolved to see the reflection of radio waves, to then go bouncing high power radio signals around could potentially blind themselves so they have evolved some other means of distant communications.

That's just one failure scenario, if you took a Wifi signal and could somehow transport it back in time 100 years and blast it out at 1000 times the normal energy how long would it take past us to notice?

I think even 100 years ago, a kilowatt microwave transmitter would probably draw attention to itself by the way that eggs explode and cups of water boil when near it.

Fair point. Call it 60w or even 1w if that feels better. It's still many orders of magnitude over what you would be receiving across space from another solar system.

Also, for mild amusement, your comment reminded me of this video https://www.youtube.com/watch?v=b9UO9tn4MpI

You would have to stand right next to a 1kw microwave transmitter to notice any heating effects. That wouldn't help you locate it at any distance.