reprinted courtesy of ServiceMagic.com
Outdoor electrical
systems require special care, equipment and materials such as
weatherproof electrical boxes, conduit for all above ground wiring
and weathertight connectors. Any outdoor receptacles must be GFCI
(ground fault circuit interrupter) protected and usually kept
on a separate circuit from lights. Failure to do so can cause
or contribute to the failure of the lighting system.
-- Tips courtesy of Service Magic