ok, I have a script that may work for you .

stupid Poser and Python made it harder :(    but thats to be expected :-)

The script stores the intensity of all lights at frame 0 so the scene can be lit as desired.
it steps through each 30 frames and adds a random number between 1 and 9 for each light so they dont all change on the same frame , and randomly turns them on or off by setting the intensity.
A constant interpolation is used for the intensity parameter so the slines dont mess it up and double keyframes can be avoided.

The frame count and random frame can be altered - read the comments in the script.

script attached, rename as randomlights.py  or whatever name you like