solar3000 wrote:Do you have a very long stick?
Are you comfortable with opening up that panel? You could wire up a very simple circuit. A low power relay would work well. It would be the same as you pushing a button. And how many buttons will you be pushing? Or will you push them ahead of time and trigger the last button remotely?
I would not recommend opening the panel. I assume it is near the sauna itself, and will involve mains voltage. It may have been built with very particular regulations for saunas in mind, so any modifications should meet the same rules. The chances of inadvertently doing something wrong are not small.
In the absence of built-in remote facilities (and assuming an upgrade is not available) I think a robot arm is the way to go. You will need a web-based remote service. I think Mosquito does the job, though I haven't used it. To maintain security of your home network it is best if the Pi calls out to a hosted database (even if the data is only on or off!), otherwise if you need to "phone home" you must pay attention to changing account names and passwords, introducing better validation, and other methods to keep the bad guys out.