When planning a lighting system there will often come times where standard light fixtures simply aren’t appropriate, particularly for wet areas like bathrooms, outdoor areas, water fountains and swimming pools, where the risk of water entering the light fixture is far too great.
In these situations you will need to ensure that the fittings you are installing the lights into are completely weatherproofed or waterproofed. Electricity and water don't mix well, and with all the steam and potential water splashes that a water feature or shower produces, you need to be sure that the two don’t cross paths. The most important thing to do is select a light fixture that is IP67 rated, which means it has been stringently tested to be water resistant.
How to deal with a compromised fixture
If there is already a light fixture installed in your bathroom and you are concerned that water or steam could be penetrating it, the solution could come in the form of a tube of silicone caulk. You should have the outer edge of the fixture sealed with it to avoid any potential danger.
If you have any doubts about the weather sealing of lights that are likely to be exposed to water or steam (pool lighting and garden and landscaping lighting in particular), you should contact a licensed electrician to have it inspected and tested before using it again.
