I have a hallway light that can be turned on from 2 separate locations. 1 spot upstairs and 1 spot downstairs. Of course the kids dont know how to turn lights off so I want to install an occupancy sensor to shut it off automatically. I purchased the Lutron Maestro MS-OPS5M. My question is can I/do I need to install 2 of these (1 Upstairs and 1 downstairs) for the same light or do I need to utilize the companion switch (Lutron MA-AS) in order for it to work properly. Thanks in advance.