If you do not feel confident that you can handle the electrical work involved in the following article, hire a licensed electrical contractor to help you with this phase of installing an electric skylight.
If you do feel confident, start by turning off all power to the part of the house where the skylight is housed.
The electrical wires of the house need to be connected to the skylight's motor, which operates with low-voltage wires and a transformer.
To do that, join the low-voltage wires of the window motor to the non-metallic building electrical wire (in this project, the electrical wire was previously used for a recessed can light) with electrical tape.
Go into the attic and determine the best place to mount the transformer. Place it in a location that allows easy access to it should it ever need replacing.
Pull the wires to the location where the transformer will be mounted.
Cut off the excess wire and insulation of both the low-voltage and non-metallic building electrical wires. Pull the non-metallic building electrical wire under the junction box and bring it through a knock-out plug.
Strip the wires and attach the black wire from the non-metallic sheathed cable to the black wire from the transformer with wire nuts. Attach the white wire to the white wire with wire nuts. Put the non-metallic building electrical wire connection inside the junction box and then mount the transformer to the junction box.