I'm personally rather sure that there could be a planet with intelligent life somewhere in our universe. The chance is minimal but due to its sheer size, I don't think it's too unlikely.
UFOs that are supposedly alien ships, I'm not too fond of. Don't believe anyone who was advance enough to travel distances like that would want to visit our little solar system. And tbh, we are too focused on ourselves to even dream of not fucking up social relations to an extraterrestrial race.