You can fix the system in many places as you like. You may prefer to install it in the meeting rooms, corridors, parks, and cafeterias. Your servant also gets a pager. It can be wearable like a watch or a belt.
When you call a servant for help by touching the call button. A beep sound will be sent to the servant’s pager. So, he can come to your palace and do the work without wasting no time.