I have seen UFO's twice for sure,and probably a third time. All three incidents were within 100 feet of where I am sitting right now,and one incident had two other witnesses,one of whom was my elderly father. Damn thing hovered right over the house for a minute or two,didn't make a sound,and was so close and so big it blacked out the sky right above us.
Suddenly,in the blink of an eye,it just disappeared without making a sound.
The other time I was leaving home around 10 PM,and just happened to notice a "black spot" in the sky. Stars everywhere but there. I thought "what the HELL?",and got out of the car to see and hear better. Had no idea what it was then,or even now. What I DO know is that suddenly there was a loud sound EXACTLY like that made by old-time light switches that had pull chains on them,and a whole section from the black spot in the sky to the marsh was lit as bright as day. That lasted for maybe 15-20 seconds,and then the light just went out without making a sound,and the black spot in the sky just disappeared.