We've all seen Susan Boyle off BGT.
But I haven't seen a UFO in a concrete way, but I have definitely had nights where my room starts getting extra breeze and outside my window gets an extra burst of wind, the bedroom walls go a bright yellow colour from the noise that's hovering around outside, and I hear the actual Vehicle (or whatever you wanna call it) making vacuum type noises even though it's hovering in the air.
I mean tbf it could just be a Helicopter or a Plane, but it creeps me out when it sporadically happens.