Flashing Lights
I've done a similar effect by making a small flic (100X100 I think) 60 frames
long (or however long the period of the light is), the first half of the
frames were pure white and the last half were pure black. Then I used this
flic as a Self Illumination Map for the light material. It saved me from
having to mess with the Hide keys, and it allowed me to have alternately
blinking lights just by creating a duplicate material except turning on the
negative button in the Self Illuminating Map Setup. You can also use the same
flic on an animated spot light to flash on the surrounding object fairly easily
this way.