To be able to build a zigbee unit that could fit in a standard wall box, I had to do rebuild the triac unit using smd parts. I always thought that this technology was difficult for diy projects, but that proved to be wrong. Using solder past and a heat gun makes building a pcb with smd parts easy.
I designed the pcb, and had it fabricated in China. After sending the gerber files, it took only 7 working days to receive 10 2-layer proto boards. I also ordered all components from China (which took a little longer). I did not use the zigbee controllers from Netvox, but ordered some cheaper parts which are also based on the TI cc2530 chip.
The connected light can be switched and dimmed locally by the 2 buttons. A locally changed state will be reported to my home control program.