Toller wrote:
I want to put up a new fluorescent fixture in my basement. Right where I
would put a box for an outlet, there is a cable for an appropriate circuit.

The circuit was put in pretty sloppily, so I was able to get 4" of slack
right where the new box would go. Is that likely to be enough wire to add
an outlet? Seems adequate, but I don't want to cut it up and find I needed
5".

Cut the wire, insert both ends into the junction box, strip romex
jacket back inside the box, strip the colored conductor insulation back
as usual, twist the wires back together, add three (hot, neutral,
ground) 6" lengths of insulated wire (correctly color coded of course)
and twist one end of each wire to the corresponding splice, wire nut
each connection. You've just installed pigtails that conform to code.
Proceed with wiring the fixture as usual.

R