If your pool lights were installed by a reputable pool professional, they probably are.
Pool lights need to adhere to the National Electric Code, Article 680. In this code section, the pool light fixtures need to be UL listed. UL stands for Underwriters Laboratory, a private firm that does rigorous testing on all sorts of products.
The pool light should be on a dedicate circuit breaker and protected with a GFCI (Ground Fault Circuit Interrupter).
In addition, pool lights need to be properly bonded and grounded per the National Electric Code. Most people have a little confusion with bonding and grounding. They are two separate things. Grounding ties the light circuit to ground or earth. It allows electricity to flow back to the breaker so it will trip if there is is short circuit. Bonding actually ties the pool and other equipment components to the steel rebar of the pool structure. This allows electricity to flow to the rebar in the pool structure via a thick copper wire. Incidentally, electricity will always follow the path of lease resistance. In this case, electricity would rather travel though this bonding system then your human body. If there is a failure in the bonding system, electricity will consider your body as the path of least resistance. Not a pretty picture.
While pool electrocutions are rare, they do happen.
Here are some tips to ensure you pool lights remain safe:
1. make sure that water stays out of your pool light fixture.
2. regularly test your GFCI.
3. have you pool lights thouroughly inspected.
4. use only a qualified and licensed contractor to repair or replace your pool lights.
5. consider changing your 110 volt pool lights to low voltage lights.
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