Whether we realize it or not "Radio" it lies at the heart of earthly communication systems. It is coupled with Microwaves in some cases such as satellite communication. Radio is the backbone of systems like television, wi-fi, bluetooth, cellular, and probably a half dozen other related systems. Radio relies on electricity and magnets to produce a signal most often in patterns that can be translated via receiver in each and every form that I am aware of. Similar systems are employed to send most point to point digital signals, even if they do not rely on radio. In every case these rely on electricity and magnets.
Steam Engines & Other Curiosities
Prior to gas powered engines, vehicles relied on boiler systems to power a drive train by turning a connected mechanism like a gear which in turn pulled either a pulley or a chain connected to another gear and in turn moved the wheels along. Versions of this and other non electrical system have been around since ancient times and in some cases, even without the engine, this kind of ingenuity incorporated hydraulics, levers, wind power, lighter than air gasses, floatation, gravity, etc. The commonality being no electricity, as the theme in such innovations as can be imagined.
Why Mention This
Electricity as a medium for Earth's mechanical and now communication needs is a great achievement. We certainly wouldn't have radio without electricity and therefore wouldn't have an internet, or television etc etc. If our civilization had relied upon it however, we'd never have arrived. We didn't always have it, and may not rely upon it in the future if certain other technologies open other avenues. Zero point energy fields or even quantum energy might radically change the way we send signals across the planet and most certainly would change communication at a distance and so I've often wondered how new communication technologies might look. LiFi is perhaps a poor example because it relies on electricity but rubbing two pieces of copper together can create sonar. The difference is perhaps the speed at which a signal might be sent if an exoplanet was using a different energy altogether. Can Seti spot a quantum signal? Can it spot Li-fi? Are there plans to incorporate such technologies for listening purposes in the near future?
Earth has a history of innovation stretching back quite far and if it has shown us anything it's that new technologies improve our reach if not always our grasp of what is or is not possible. Life on other planets seems like a distinct possibility and when you visit someone who hasn't ever used social media ask yourself what that must be like. If Earth were strictly Amish we might expect to find other Amish out there but most of us who are not Amish use electricity. Does that change what we expect when we search? Would Quantum signals be faster or slower if instead of electricity it ran on zero point energy or some naturally energetic field? Would a light based transmission be visible light or invisible light and how fast would it pulse if it were powered by explosions instead of electricity? I guess the moral of the story is with so many ways to accomplish something like long distance communication, how do we spot interstellar smoke signals if that's the newest standard? I invite authorized members of Seti to respond here and use the responses in any way they like. Maybe something for the next Ted talk.