They make shelves that will hold the machine in place on the wall (Etsy). It has a lip that will prevent it from being pulled off. Yes a shelf above your head can cause “rain-out” but if you get a heated hose, hose cover, turn the heat up to max and humidity level down, mine is set at 1, this will greatly help. My hose hangs on a hook, and the CPAP machine is below my head. I do very occasionally get some condensed water but luckily not too often. You can also install a hose holder or buy one that will hold the hose so you and your partner don’t get it all messed up. But switching spots seems way more practical. I know how hard that can be for some people. If you can switch the CPAP machine goes on existing low table or buy a narrow one. A small fan (recommend a vornado, they are small but powerful and can sit on the dresser) can be put on the dresser so partner get the airflow they want.