Growing up, I was used to lights, the back of the house I grew up in backs up against a parking lot and then to a major street. Police would park in that lot or the one next door for speed traps, so flashing moving lights was never worrying to me. But I have to explain how the bedrooms on this house are set up so you can understand what's so weird.
Three bedrooms, side by side, on the north side of the house. Mine was the furthest east. Mine was at the end of the hallway. Open my bedroom door, you've got closet on the right, bathroom on the left, corner in the hallway a bit in front of me, then the hallway turned west. Next bedroom opened straight into hallway across from the big doorway to the living room. Third bedroom opened straight onto the western end of the hallway. And the south side of the house was on a tiny horseshoe residential street, NOBODY went on that street at night unless they needed to.
So I got up from my bed one night to go to the bathroom. I saw a light bobbing along the hallway. Which was around the corner from the nearest window, and it's the window that never gets any light anyway. Curious, I follow it. It literally bobbed along the ceiling like a balloon until it got to my parents' room, the furthest west. It went through their door, then came back and bobbed its way back to my room before it disappeared.
There is no way any outside light source could do that. Nobody else was awake. And that was the only time anyone in my house saw the ball of light. Plenty of other things going on, but nothing ever like that again.