Horea, I'm quite sure what you are describing is a 3-way switch. Check the switch, it should not say on/off on it. If it does, it will be a first for me. A three way will not have any writing on it. The only thing is where is the other end hiding? Sometimes in a remodel I will disable one end by nutting the black and white together and putting a blank on the box. This allows the other end to act as a single pole. See if you can't gather some more info for us, like how many wires are in the light fixture boxes. Maybe we can help you out with some of those old school tricks. Let us know, good luck....
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