Looking for some help coming up with a clever solution to a problem that doesn't involve wrecking the house! :-)

The scenario is that our downstairs rumpus room is accessed through a door off the entranceway of our house. Off the other side of the rumpus room is a hall with two bedrooms, a bathroom and a laundry. The light switch for the rumpus room is beside the door to the hall. There is no light switch on the entranceway side of the room so, at night, you are wandering around in the dark to get to the other hallway.

The two doors are relatively opposite each other so I had previously installed a unit from HPM (HPM DXL632) which was a light switch with a built in motion sensor so that the lights came on when you entered the room and then turned off after 30 seconds or so once you had passed through. You could also manually override this and just turn the lights on if you were in the room for a while. This worked well until a number of years later the unit failed. So I replaced it... and then after a number more years it failed again. (starting to sound like a Monty Python gag about castles built on a swamp!) This time, I couldn't replace it because HPM had stopped making these units and I couldn't easily find a similar unit from PDL or others.

The wall between the entranceway and the rumpus room is concrete block that has been lined with gib and would be a bugger to try and run cabling to which is why I expect there wasn't a switch installed there in the first place. 

Other than hacking holes in the walls and ceilings and installing a proper two-way hard wired switch, are there any other clever options available these days that people know about that?

Thanks