Electrical codes universally require GFCI (Ground Fault Circuit Interruption) receptacles within so many feet of a sink or bathtub, and we should all treat our aquariums the same for our own safety. You won't hurt your fish, but you could get a very dangerous shock or be electrocuted by the combo of electricity and water. You can get a GFCI at your local big-box store for around $20.00, and installing it is pretty straight forward. If you're not confident about re-wiring the receptacle you plug your aquarium stuff into, you may be able to find a plug-in adapter, but they're not as common. Hire an electrician if need be! (I was an electrician in an earlier life)
A GFCI keeps track of the electricity coming out into your appliances, lights, pumps, etc...., and makes sure the same electricity is going back in through the neutral. It's more complicated than anyone needs to know for this purpose, but the idea is that if it senses electricity going where it should NOT go, like into your body!! -- it will nearly instantaneously turn off the power. They save lives every day.
Please be aware that a "surge protector" strip or adapter is NOT the same thing. Make sure it says "GFCI". Surge protectors don't care about you, just your appliances, saving them from occasional power surges that would fry their innards.
As for the light, I've not much to add to the earlier response about just giving it plenty of time to dry out. I might recommend parking it on top of a heat register or radiator for a while to help drive out the moisture. If you could disassemble it, might help.
Stay Safe! :smile2: