A foldable half sockets to form complete sockets for Christmas lights includes a V-shaped double sockets fold away of a pair of V-shaped half sockets in opposing symmetrical arrangement connected by a pair of thin membranes and avoid therebetwen. The sockets each has a pair of longitudinal slits, a pair of indentations in their lower peripheries for passing through a pair of electric wires each with a single contact plate on the top. A V-shaped groove formed in an inner periphery of the sockets for engaging within a V-shaped common contact plate. When the half socket is folded away, a pair of sleeves wrapped thereon. A pair of lamps insert in the sockets each has a longitudinal flat extension inserted into the longitudinal slits and a pair of lead-in wires respectively engaged with the common contact plate and a single contacts respectively.