Be forewarned: tp-link did a poor job designing the switch housing dimensions. The switch will not fit in a standard 4" steel box. The switch housing interferes with the faceplate mounting screws . Why is this a problem? If you bought the switch for automatic control of porch lights AND you have (2) 3-way switches AND one of those switches is installed in a 4" steel electrical box, the switch housing will not clear the faceplate mounting screws. Obviously, you could rip the old box off the wall and install another box but, what a shame: all because TP-Link didn't make sure the housing fits in industry standard boxes?

No idea if you can cut-a-way the corners of the housing to gain clearance. But even if it works, you will be voiding their warranty. If anyone knows of  a different solution, feel free to reach out.