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