Chris wrote:
about a year and half ago, I had a security light installed on my
garage with a day/night sensor. Latley, I have been noticing the light
flickers.. not a quick flicker, but inconsistent alternating levels of
light amount coming from the bulb (mercury vapor bulb).. it is kind of
annoying.. It has been working great up until recently.

Before I wonder if the power wire to the garage should be replaced, or
I start replacing fuses.. is this a sign the bulb is just going bad?
it is wet and cold right now.. a normal variance? I never noticed this
before..

Hi,
if anything is going bad, it is the sensor itself. Cover the sensor to
see if it does yet, then it is sensor not conducting fully when dark.