I picked up a set of 4 replacement rocker switches for my 2010 XC90 using the part number helpfully provided above (31295247). When talking to Volvo they said the system stated the part would fit the passenger door of the XC90 and all doors on other models. But thought they would be universal for the XC90 too.
I successfully replaced two broken switches on the front driver and passenger doors. One came off with some effort, but intact the other disintegrated as I tried removing it, but happily, both were easily replaced by popping one of the new rockers on.
Moving to the rear passenger side door, the switch was completely destroyed in the removal only to find the replacement switches didn't fit!
I called Volvo who said they had found an alternative switch for the rear doors costing £40 each! Fortunately, eBay saved the day and found a replacement unit, with minimal cracking for £10. They all look the same, they are not!