It depends on what you intend to do with that 10-volt output. How much current is needed? I assume you want +10 volts DC when the button is pushed.
If you don't need much current and if you are not concerned with safety, you could use a resistive voltage divider followed by a half-wave rectifier and capacitive filter to get the +10 volts.
If you need more current or you are concerned about safety then get an isolation transformer with a 220-volt primary and a 10-volt secondary and make a little power supply.