I was wondering if you would pass a hair test for EtG metabolites if you are a very light drinker... 2-3 drinks a week?

Normally no, you will not pass, if the guidelines for the test is no drinking at all. If you are under some rule, not to ever drink, then it will show up.
Issues will be what is being drank, how many hours before the test, what is the limits on the test (they all differ depending on the rules of the test) body weight and so on.

People fail through incidental exposure all the time so why take a chance by adding to that risk by being a light drinker? I doubt anyone would tell you it's okay to have a few drinks a week while subject to such testing. Who would you blame for failing a test?

If it gets into your blood stream, then filtered out by your kidneys, then it will be deposited in the hair. Light drinker or heavy, it will show up. So no.

Aren't the requirements NO drinking?