The first blue light I saw was last year. I don't sleep very well so I usually get up and go downstairs and read until I feel tired. I decided to return to bed so I switched off the lamps and was making my way to the stairs when a blue light on the ceiling caught my eye about 5 inches in diameter it had lines through it and it was dark blue it didn't move. I ran up the stairs because for some reason it scared me.
I told my husband the next day and we both tried to figure out what it could be there was no logical explanation. A few weeks later I got up again for a drink as I came do the stairs I looked at the ceiling and the light was there again but slightly paler and smaller not moving. I had my drink but on the way back it had gone. The next night me and my husband looked at all possibilities what it could be but nothing.
Last night I came downstairs again, had a sleep on the couch and decided to return to bed as I got halfway up the stairs I looked into the living room as it's open plan; the room turned a vivid dark blue. Everything was blue. It couldn't have shone through the window and there was nowhere else it could come from, no explanation whatsoever. It can't have been any of the emergency services that sometimes pass the house as that light is completely different and that moves as the vehicle passes.
I find it all scary as I don't know what it is. We have been in the house 18 months and an old lady lived here before. We have had lots of electrical problems even though the house was rewired when we moved in; lots of strange noises, items being moved and we have heard bells tinkling it's all very odd.