I have two small bathrooms; they are on different floors; the upper one is somewhat above the lower one. An outlet in the upper bathroom is connected to the GFCI outlet in the lower bathroom. I am inserting a photo from the lower bathroom. It shows the GFCI outlet on the wall on the left side of the vanity.


The reason tools are laying around is that I just replaced the GFCI outlet; the old one was the original and was about 31 years old.

I would like to add an outlet on the right side of the vanity cabinet so that a small heater could be plugged in to it, and thereby not have a cord run over top of the vanity cabinet. As configured now, an outlet in the upper bathroom is connected to the GFCI outet in the lower bathroom. No additional outlets exist on this GFCI circuit.

The walls in both bathrooms are wallpapered. I'm wondering whether, or how, a GFCI-protected outlet can be installed on the right side of the vanity cabinet without having to cut holes through the exposed wall areas. Cutting through the left side of the vanity cabinet (below the sink) and through the wall there would be alright. But, I don't know whether the installation of the desired outlet can be done without cutting into walls (lower bath, upper bath, or both) where the cuts would be exposed.

Edit: I just realized I have overlooked an obvious point. The wall surfaces opposite the papered wall in the bathroom are not wallpapered. So, any cutting of walls should/could be done on the outer side. Then, the repair would involve patching the drywall and touch-up painting.

 

Now that I've recognized my faulty thinking about cutting of the bathroom walls, I think I should delve more into the electrical technicalities.

As stated in my original post, I believe the only outlet supported by the GFCI outlet is the one in the upper bathroom. Based on my limited knowledge about this, I am thinking an additional outlet would have to be connected to the outlet in the upper bathroom, i.e. the outlet supported by the GFCI outlet. [in case this might be helpful, let's say the GFCI outlet is labeled A and the supported outlet in the upper bathroom and labeled B, then, a new/third outlet would be C.] So, a wire would have to be run from the outlet in the upper bathroom down the wall and through the floor, continuing down the wall on the lower floor far enough to then route it either through the wall and left side of the vanity cabinet and then passing through the vanity cabinet to the right side of it where a hole would be cut and an outlet box mounted.

If running an electric line through the vanity cabinet violates local building code, then ... Well, perhaps we don't need to get into this yet.

 

It doesn't have to.
You can connect to load side of existing GFCI by making a splice or straight into the terminal.
Each terminal of most GFCI receptacle can take 2 wires under the screw.

If you are ok with patching and painting ceiling, the ceiling probably is the easiest path.

You can cut existing junction box out without cutting drywall. You can do this by inserting hacksaw or sawzall blade between stud and the junction box and cutting nails on top and bottom of the junction box.

Then, straighten wires and pull the box out.

Now, you can cut a large hole on the ceiling above and either use existing hole or drill a new hole on top plate, fishing wire down the wall.
Do the same for the new location of new outlet.

You probably will have to cut multiple spots or just cut a long strip of drywall to run wire through joists.

Install old work/remodel boxes at the new location and existing location.

 

dderolph:
A couple of thing you may want to consider before going thru with this project of tapping into the existing circuit to run a plug-in space heater. You will limit what else can be plugged into this circuit and used like a hair dryer while this space heater is running. You will more than likely trip the breaker.
Hair dryers run around 1450 watts and the space heater probably 1500 watts.

Space heaters also should not be left unattended for periods of time. They tend to heat up the receptacle and may cause melting or burning of the receptacle. Space heaters are also not meant for a main source of heat in a room.

I don't know if you realize these facts. Have you been running a space heater already in this bathroom?

You may want to consider running a dedicated circuit from you breaker panel to the bathroom and using a hardwired heater which will be much safer than a space heater.

 

Nitpicking.
If the circuit serving the (ground fault circuit interrupter) receptacle in the first bathroom also serves a light or fan or other item then you should not tap off of it to go to the second bathroom or other room. Otherwise it is disqualified as possibly being a required bathroom circuit for the first bathroom. Meanwhile a new 20 amp circuit direct to the second bathroom can become the required bathroom circuit for that bathroom. (One branch circuit can serve two bathrooms if it is receptacles only and any different circuit can serve the lights.)

 

lambition,, I think I get your suggested approach. I think I'd want to use my oscillating tool to do the cutting you mentioned to cut existing junction box out. And then, you suggested running a wire up to the ceiling and cutting a large hole in the ceiling. That makes sense but the ceilings here are textured (done during original construction) and I'd have to try restoring the textured look where ceiling cutting was done, and I'm sure I can't perfectly do that. I guess I could remove the texture coating in that bathroom.

AFJES:
I have used a space heater for years in the upper bathroom but not the lower bathroom. Both bathrooms have a heat registor for heat from the furnace. But, I keep the home thermostat a bit low during winter and like to have some extra heat in bathrooms at certain times. I have purchased a wall heater for the upper bathroom but don't have it installed yet. It will be hardwired. The lower bathroom is the smaller of the two bathrooms and I have always thought it just doesn't have enough available open wall space to install a wall heater.

AllanJ:
The electrical line supporting the GFCI receptacle in the lower bathroom does not support any lights or fans. The only additional feature it suports is an outlet in the upper bathroom.