In 1967 my mom and dad moved into a new home on Waverly Court in Upland, and of course I still being in high school went along because after all, the kids always go where their parents move to.
I soon discovered that on certain nights in my room a blue light would appear on the ceiling of my room. The first time my dog woke me from a sound sleep barking at the light as it drifted down the wall then went it out as it hit the floor.
The nights it would happen were usually very foggy, moist and drippy out side. Out side my window at that time was an orange grove. When it was clear I never saw the light, but on nights like I described, I would sometimes see it, not all of the time.