Tiles of light by annick collins from uk

After attaching the tiles to the wall, weave either optical light fibre or
electroluminescent through the channel, then grout the gaps between the
square tiles. Then connect the light source up to a supply and see light
peeping out of the tiles. This concept gives you creativity as you can weave
the light source through the different channels.
Or alternatively, you can also weave wire through that will have a low
voltage. Then pushes little led flies into the gap and see them light up.