I've thought for many years that SETI is scanning the wrong band. They're scanning radio frequencies, but I don't think interstellar travelers would use radio at all. The fact that SETI has been scanning the heavens for so long, and have come up with nothing, has convinced me that they're probably looking in the wrong place.
As to what band SETI should be scanning, I don't know, but I do think that they made a fundamentally flawed assumption when they decided to scan the radio band.
You talk of never having seen any kind of evidence that ET exists. My son and I witnessed something once that was beyond any technology that I know of. I don't claim that what I saw is evidence of ET, but it was so far beyond any technology that I've ever seen or heard of, that I can't believe it was ours.
“I’ve thought for many years that SETI is scanning the wrong band.”
Well, I do not know what else they could scan?
To my knowledge, they scan a very broad range of frequencies, all with automated receivers.
One of the origins of SETI was from the mid 50s, some 20+
years from the first TV signals that were broadcast.
Since they were on VHF, they would pass through the ionosphere
and continue on into outer space.
Eleven years to the nearest star and eleven years for a reply.
Well, that was the basic concept.