As stated, raised ranches are pretty straightforward to retrofit, without cutting walls or the like, as stated, you only need to really know how they would be framed and put together, and literally, you can run wire pretty easily in them once you know the secrets and where there are voids and joist bays (you'd really be amazed once you saw someone fish them).
That said, with vinyl, there are a few ways to go, but for soffit, you're going to need to put a 3/4" hole typically. The camera base plate, assuming dome or bullet/turret, should have enough meat where you can pick up a rafter tail and call it a day.
Sidewall mounting, either leave them somewhat loose so the siding doesn't buckle, then use an appropriate sealant (silicone or ductseal) to weatherproof behind and the wall itself.
If you really want to go overboard, then you could pick up siding blocks, either to match your siding, or for universal lighting boxes (Arlington comes to mind, used on my house) and then mount the camera to them. Arlington also makes a lot of products that could be used otherwise.