[takeitapart2fix]

I'm trying to make sense of the wiring and switches in several of our bedrooms. Our house was built in 1966 and there are very few overhead lights in the rooms. However, most of the rooms do have switches on the wall. In one of the rooms the switch controls the bottom plug -- which I guess this is what is referred to as a "half-hot" receptacle. In all the other rooms the switch does absolutely nothing. But they are still wired to the switch. See the attached photo.

This wiring is actually typical in every room that has a non-operable switch. I think the wiring was at some point altered from it's original wiring. If I disconnect the white or black wires it disconnects the outlets in an adjoining room. The red wire and the black pigtail were connected to a switch. Again, the switch did absolutely nothing -- so I can touch these together or not, and it doesn't matter.

I assume if I can solve the puzzle for this one room I'll be able to sort out the remaining rooms. Thoughts?

 

[joed]

Someone swapped out the switched receptacle at some point and probably did not cut the tab on the hot side.
If more than one switched receptacle is present, it only takes one tab not cut to apply unswitched power to the switched side.

 

[dmxtothemax]

As you suggestted, someone has changed the wiring,
possibbly because they did not understand it,
The switch loop is probably not connectted up any more.
we need to see pictures of the wiring at both points
I.E. - the receptle and the switch.