Rewiring old house to code. Notice that most (if not all) wired smoke detectors have a base plate that the main unit attaches to, mounted to ceiling/wall with 14/3 wire dropping through middle. Generally speaking, for rough inspection purposes, is it best to plan to mount the base plate to a can, allowing for the inspector to see the drop in some type of container instead of just hanging there stapled and waiting for celiling to go in or (where ceiling still exists) hanging out of a hole?

Smoke detector wiring is 120 volts, and each smoke detetor needs to attached to an outlet box containing that wiring and splices.

For rough in purposes, all outlet boxes are to be installed, and all cables spliced in the outlet boxes. The mounting ring of the detector does not need to be installed on the box, until trim and finish is done.

Tkrussel - Thanks! That's what I figured and its good to have it confirmed.