About a month ago, around 9pm one Sunday evening, I was watching television. Suddenly a very bright 'white gold' glow appeared to enter through the glass of the patio doors. About the size of a golf ball, the speed of it made it appear to be elongated & at first I thought it was a light reflection from inside the room. In the blink of an eye, it suddenly disappeared back out through the glass door but at the same time almost appeared to 'disintegrate'. Looking around the room to see if it was some sort of reflection in the mirror (opposite the door), there was nothing to see different from normal. Looking across the water (we live near to the coast & can see it clearly), I thought I could see sheet lightening but not 100% sure.
The next day I googled ball lightening - I think this is what I saw (this YouTube clip captures it very well although the ball I saw was smaller):
By the way, my partner was in the room too & he jumped up at the same time I did with the same thoughts.