2 way lighting

hole cut in  wall to access switch from adjoining room

So, you want to be able to switch the lounge lights on from your dining room....you could always cut a hole in the wall so that you can reach your hand through to the switch....Or... you could call your local electrician who could install a second light switch, creating 2 way switching, for you in a more conventional and satisfactory way

I came across this in a house recently, the only explanation we are able to come up with is that it was done to enable the switching of the lights in one room from the other by reaching your hand through the hole. 2 way lighting really is very simple to achieve and this example here would have been inexpensive, quick and easy to install