Question about using refrigerator for 2nd fermenting???

I have had my brew in the secondary fermentor for about 5 days now. I put it in the fridge because it was recommended to be at around 40F since its a Pilsner brew. My question is does the light hurt my beer when I briefly open my refrigerator door? It's not continuous light but only 3-10 seconds at a time. Am I hurting my beer to exposing it to the light bulb in my refrigerator when I opened the door to get something out???

No. Not for such a short time. You'll be (or at least your Beer will be) fine

+1 on no-harm, no-foul.

If it really worries you can unscrew the lightbulb.

Old black t-shirts are great to have around in the brewery, slip it over the carboy and there ya go, no light (at least for the most part)