I have slightly less patience with UFO stories than predictions of a second coming. I put both on about an equal footing of amounting to anything concrete (that being a zero chance).
I do believe the odds are in favour of extraterrestrial life.
They may even be in favour of extraterrestrials with technologies beyond our own.
That those technologies would permit visits to earth I rate considerably less likely.
The chances that there are extraterrestrials regularly visiting earth and behaving in the ways attributed to the various unidentified lights seen in the sky I put as close to zero as makes no difference. As with many things I rate as unlikely I'd love to be proven wrong.