Working in the unfinished attic space above the new fixture location, measure the distance between the two nearest ceiling joists. Cut a 2x4 to this length and attach a new, fan-rated outlet box to the midpoint using deck screws.
Hold a piece of plywood against the wallboard at each stud and press the crowbar against it to pry the molding off. If you have two-piece baseboards, remove one piece at a time starting with the base cap and then remove the wider parts.
Place the hooks so they point in a clockwise direction and the insulation runs all the way up to the screw. Don’t leave any bare wire between the terminal and the insulation. Tighten the screws to clamp the wires down. Same goes for clamps that are tighten over a straight wire, there should be no bare copper showing.
Or if you are using a receptacle on an upper floor to serve a new ceiling fixture below, it would have to be run through the soleplate and possibly some flooring, and into the ceiling cavity below. A switch loop will also have to be run from a wall location in the room below, to the new ceiling fixture.