toller wrote:

Even if it wasn't insulated by from the water, why would it want to go
through you? It has an almost perfect ground right there in the fixture.

It's certainly possible. Consider this:

"In May 2002, a 14-year-old girl from Arlington, Texas, was electrocuted when
wiring problems in an apartment swimming pool’s underwater lights charged the
water with electricity. A 16-year-old boy was seriously shocked when he
jumped in the pool to try to save the young girl. Another teenager used a
fiberglass shepherd’s hook (a non-conductive device) to pull both victims
from the water. "

http://www.cpsc.gov/cpscpub/prerel/prhtml03/03125.html