What's this red cabin light indicator inside a Boeing 737? What's this red light indicator inside the cabin, its flush with the sides of the plane. The exact location would be a couple of rows ahead of the overwing exit seats.

This picture was taken before take-off. Forgot to observe the light after take-off. This is not a flight-attendant call indicator.
I found this pertaining to the new interior design of some Boeing737(s), I can only guess the coloring is from one of the mood lighting (Blue or red) has a defect in the connections.https://www.airlines-inform.com/flight-reports/amarchukov-1754.html