It is not hard to get this achievement but I had to try many times, somehow I guess I was forgetting each time one switch somewhere. Thanks to "Maluno" for pointing out that two rooms/switches upstairs were missing from this list (laundry room and red storage room).

DOWNSTAIRS:

The lamp you unbox:











The lamp that is already on the table next to it:











The switch out of the kitchen:











The bar has a switch and lights up actually:











The broom closet next to the bar:











The room adjacent to the broom closet:











The powder room next to the previous room:











The study:











The dining table area has a switch behing the tree:











The kitchen:











The corridor behind the kitchen:











UPSTAIRS -----

Upstairs, right where the stairs end:











Each bathroom has a switch on the wall:











Sauna in master bathroom:











Shower in master bathroom:











Toilet in master bathroom:











Mirror has a light next to master bedroom:











Reading lamp in master bedroom (have to unbox it):











Wall switch in master bedroom:











Corridor from master bedroom:











Guest bedroom reading lamp:











Guest bedroom wall switch:











Guest bedroom, wardrobe, mirror lamp:











Second bathroom: wallswitch:











Toilet in guest bathroom:











Shower in guest bathroom:











Second corridor floor foyer (from guest bedroom):











Laundry room:











Storage room: