I need to add a room wall receptacle between 2 existing receptacles. The purpose is to provide a receptacle closer to a table lamp. The current setup uses a long extension cord. I'm assuming that there will not be enough slack between the 2 existing receptacles to provide adequate length to wire in the new receptacle. Should I run a new cable from the receptacle that is supplying the power and wire in the new receptacle or should I add 2 new receptacles between the 2 existing receptacles...one of these 2 new receptacles could be a dummy. I can see the first option having a potential problem if the existing hole through the stud is too narrow for a second cable.

 

Judgment called based on the layout of the room but if it makes sense to add two receptacles, that would be my plan.

 

If you cut the existing cable you will not have enough to make the connections in the box. You will need to add more than one box.

Lamps come with 6' cords and receptacles are spaced so that no space along the wall is more than 6' from a receptacle.

 

The cord will reach but is unsightly so wanted a receptacle closer. 2 useable receptacles, 1 useable receptacle and 1 receptacle with a dummy cover plate, 1 useable receptacle and 1 junction box. All 3 options legit?

 

The last two are the same thing. No such thing as a receptacle with a dummy cover plate so what you really mean is a receptacle box with a cover plate. That is the same as your third choice. Just to be clear a junction box can not be buried in the wall. You would have two receptacle boxes both of which would remain assessable regardless of whether you put a receptacle in them or not. Therefore option one makes the most sense.

If you have an unfinished attic above or an unfinished basement below I'd go with option-4. Just fish a cable through the wall up or down and over. Your way there will have to be wall repair. No wall repair with option-4 if you are careful.