How do you splice a cut wire for outdoor lights?
To join outdoor wire (UF), purchase an "underground splice kit"
for each splice. Follow the instructions. Note that this kit comes
with a rubber sleeve that covers the finished splice and shrinks
around it using a heat gun or blowtorch (such as a plumber's
torch). A hair dryer set on hottest setting may work instead. When
heating, start in the center and move to the ends as it
shrinks.