Decorative lighting contained within a flexible linear tube, varying in diameter from 3/8" to about 7/8".
Incandescent versions have almost been completely replaced by
LED versions. Often wired in 4 circuits to allow for a
chase, and used to outline scenic elements.

Photo from
Chamanlal and sons - Products and Services.
See also
http://www.ropelight.net/ and
RopeLight Central - Rope Light flexible lighting ordering and information, as well as this thread on
safety:
http://www.controlbooth.com/forums/n...00-damage.html.