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Correctly done, the installation will have split the duplex outlets so one is switched and the other live if so. There haven't been hundreds of cases but it certainly wouldn't be the first time when I've discovered a room was that way and the homeowners were completely unaware of it being so...
I'm presuming a spot fixture probably isn't in a central location, but OP hasn't blessed us with any excess of data on which to do more than speculate...