One light switch controlling multiple lights
I read your question and the many comments and answers. There is one answer [retired Master Electricians] and one comment [ Ed Beal's ] that I would advise to consider as they provide valuable insight to what could be wrong and specifically ed's comment that there is most likely a simple solution for your problem that you yourself can solve with a little knowledge of being safe with electrical wires and some direction. I add my own answer here to assist you as well.

I think this is what happened: someone rewired that specific switch and instead of placing the continuation wire in the wire nut on the supply line in, they placed it on the Load side of the switch. I will have a diagram of what I believe you have. And what you need to do. There is a SIMPLE FIX for this issue.

In regards to some other comments:
Being as your house was built in the 1950's and not the 1930's I do not believe you have switched neutrals. The reason this was banned was that people could be electrocuted just by installing a light bulb. I am not saying this is impossible but I do believe it was codified in the 1930's. A Big clue will be that the white wires are connected to the switch terminals. If this is the case you might want to have the whole house electrical system brought up to date for the sake of your safety. 

What I believe is your issue with he solution below it :