An all-fiber nanosecond Kerr light gate is described that was constructed using microstructured fibers. The switching voltage for a 20 cm long device is as low as Vπ~85 V at a 1.06 μm wavelength. The device is fully spliced. The active element is a three-hole fiber provided with internal electrodes in the side-holes and a liquid core of nitrobenzene, which is fully enclosed. This work allows the exploiting of electrically driven liquid-core fibers and demonstrated the removal of the major limitations of Kerr cells in the past, allowing for integration, safe use, and relatively low switching voltage.