So is your issue the same, where you find yourself having to close the rear hatch multiple times to get the lights to go off?

There is a little black button on the cargo light unit which may or may not work, many of them are burnt out. You can try pressing it and seeing if your lights go out. Just another simple suggestion, your headlight switch isn't turned all the way counter clockwise by any chance? This will keep the interior lights on.

Now IMO, the most likely cause of the lights not going off the same as the original post is not the switch, but the wire is damaged and earthing out. A bad switch would cause a lack of earth, not a constant earth. How do your wires look where they go from the body into the hatch?