This may also be a different unrelated bios setting to the 'ethernet wake' setting. The power strip limits the surge current drawn from the wall inherently. When you turn on the light, the current draw goes up dramatically, but the total wattage is limited by the strip.
To keep the current draw high, the voltage sags. What may be happening is the laptop may be recognizing the sag as a power unplug/plugin event sequence. I am guessing that your computer is set to wake on power.
Simply turning that option off in the bios I am presuming would stop this from happening. You can test this by putting your laptop to sleep, unplugging it from the wall, and then plugging it back in, to see if that wakes it up.
I have seen wake on lan triggered by stray emf before, but that is a rare case, and not something that would happen every time. The wake on power setting I have seen triggered repeatedly in the past by just such circumstances.