OP
Adam W
What you're after is known as a 'last man out switch'. It's not necessarily a 'thing' which you add in though, it can be dependent on the way the house has been wired. As others have said you can install contactors on each lighting circuit which are simply controlled from a switch at the front door, like a hotel master switch, but you'd always need to remember to switch it back on when you re-enter the property, turning everything back on which was left on when you left the house, you'd need to re-enter by the same way you left, and as has already been mentioned if you have anything like outdoor security lights, alarms, clocks etc wired into the lighting circuit they will all be turned off when you leave as well.
Alternatively you could have a contactor for every light switch controlled by separate momentary push to make and push to break switches, then a master push to break switch at each exit which cuts power to all the contactors, then each light can be switched back on as needed, like a safety stop switch in a workshop.
Once you have your house wired like this it should be easy enough to swap the contactors for an intelligent lighting system, so you could turn all the lights on and off via an app on a smart phone, which seems to be all the rage nowadays.
Or as Murdoch says you could change all your light bulbs for low energy ones so it won't make as much difference if you leave the lights on,
Or you could get into the habit of turning lights off as you leave a room.
![[ElectriciansForums.net] Switch that switches off all the lights in the house](https://electricians.s3.eu-west-1.amazonaws.com/data/attachments/22/22691-c0871db430f5d6ac4e5056a0fa07227f.jpg "[ElectriciansForums.net] Switch that switches off all the lights in the house")
