This is a pair of male and female sockets for IKEA LEDBERG LED strips. This lets you connect multiple strips together over distance or at odd angles using wire. These are designed to be filled with 22 gauge solid core wire (or similar). Multi-filament wire also works if you twist it; it'll work even better if you tin it.
These connectors can actually mate with each other, so they could be used for applications other than the LEDBERG lights. If doing such, you'll almost certainly want to use solid core wire.
All units are in mm.
I track the .scad source in my The Mµseum project on github.
I printed this on a Lulzbot AO-101 using Slic3r to generate gcode. The source file has the parts rotated so that they'll print well on an extrusion printer as-is.
Assembly is simple: just cut some wire, making sure to leaving plenty of extra to fit through the connectors. If using solid-core wire, there are some extra holes to make wire hooks on the male connectors. I attempted the same on the female connectors, but it was hard to get inside the connector to bend it.