Whenever you tile a wall, whether for bathroom wainscoting or a kitchen back splash, you will likely encounter sockets. Tiling around a socket doesn't have to disrupt the rest of your tile design. In fact the tile should flow smoothly right around the socket without a problem. Treat the socket as if it was a shape you were cutting out of cookie dough. Only in this case, it's the centre you will be throwing away.
Install your wall tiles up to the area where the socket is located. Take the tile that will go over or around the socket and trace the outline of the socket on the tile with a pencil.
Cut the two outer edges of the socket tracing on the tile saw. Make parallel cuts between the two edges until the inside of the tile looks like a comb, if the socket is to be positioned on the side of the tile.
Use tile nippers to cut out the long pieces of tile from inside of the tile to create the shape of the socket on the side of the tile.
Drill a hole in the centre of the tile with a diamond-tip bit where the socket will be placed in the centre of the tile. Use tile nippers to cut out the shape of the socket from the middle of the tile, starting in the area you drilled.
With the trowel, apply thinset directly to the back of the tile to be placed over the socket. Slide the tile over or around the socket and twist it gently into place as much as possible to adhere the tile to the wall.