Dude. There are lots and lots of radio signals from space. Many occur naturally. And there is the prejudice of your argument.
SETI doesn't apply the principles of intellegent design. It uses actual science. It doesn't say "Hey, there's a radio signal, it's a sign of Extraterrestrial Intellegence!"
Instead, it looks for, and eliminates any other possible explaination. To date, despite finding thousands of promising signals, it has yet to find one that qualifies as being a sign of extraterrertrial intellegence. Not one. ID, on the other hand, makes an inferrence of a designer, but what testing does it do? Seriously, expalin the rigorous empirical process ID goes through to test any evidence it finds. How much, if any, of your evidence has been testing, found lacking and discarded over time. Real science finds its mistakes and corrects them all the time. Does ID? Cite some examples, please.