I actually am trying to accomplish something similar. I want to hit a wall switch and turn on/off the lights(replace my room lights) but I can't find any wifi switches that can control other smart devices at the same time. Closest I could come was to configure 2 amazon alexa buttons to On and Off buttons, but the buttons can't act as a toggle (1 button can't turn it on if it's off, and off if it's on) so it's kind of inconvenient/useless.
Yeah, there's a few smart things that I've thought about creating myself. I've wanted to mess around with the raspberry pi, just haven't done it yet. I want someone to create a wall switch to control smart devices through alexa or the hub.