Audio Systems: How to connect two speakers to one wire, negative terminals, negative terminal

Question
We built a brand new home with a builder.  Prior to dry walling I installed two speaker wires. Now I can find only one.  I opened the ceiling at multiple places but have not been able to find the other wire.  I am wondering if I can install two speakers in series on the same wire or can I split the wires and put each speakers on one of the strands and just use one of the inputs on the amp.

Thanks

Answer
Draw me a picture in a jpeg. I have no idea what the condition is with respect to the two speakers and the two wires. The end result must be that the poitive and negative terminal of the amplifier must be attached to the positive and negative terminals of the speaker. Any other variation must be done knowing the impedance of both and must include both positve and negative wires.