I have to agree with crosstrainer, distances are just too great. And if any civilisation does happen to be capable of overcoming all the problems of defying the speed of light ( and the problems that brings with it) I can't see them just having a quick buzz around the sky before going home. In any case we would (or should) have been picking up signals from any other intelligence, heaven knows we've been listening long enough. But nothing.
Some weeks ago there was a strange light in the sky in West Yorkshire. It made the TV news next day, and there was quite a bit of discussion. I watched it for some time (as did many others around me), jumping from one spot to another at amazing speed and could not offer any explanation as to what it was. But I saw no reason whatever to suppose it could be extra terrestrial.