@mstormi Thanks for the input. The fibaro button looks quite cool. As I do not have ZWave in place at the moment I did a little research. I would need a Fibaro Home Center to put this button to work, correct?
@Benjy A couple of seconds would be acceptable. With 5€ and no further requirements the amazon dash button is probably the best solution. I’m a newbie regarding microcontrollers and the DIY approach, though this solution sounds very interesting. I found this post Fire Alarm Button - he was using the esp8266. I think I’ll do some more research on this 