I'm a little concerned about being unable to find the pairs for 3 way switches. My niece bought a place built in 1954. She actually found the building plans in the house and framed them or I might doubt the build date. A few family members decided we would help her out and paint, change out switches, outlet and misc. The stuff a 24 year old wouldn't be able to do or afford. Once we started taking out light switches we found three of them were double throws. With the place empty and five of us looking we never found the second switch on each circuit. Those switches did have three wires. Two controlled lights and the third an outlet. I didn't mention it to the others but I was thinking during the remodels over the years someone may have walled over the other sides of these circuits. Any ideas on what is going on with that?