You probably have 220 VAC feeding the house, which is two out-of-phase 110V circuits. Half of the house will be on one of the 110V circuits, and half will be on the other. You have to find a pair of outlets (one in the house, one in the garage) fed by the same 110V side of the 220. In your circuit breaker box, if it has two columns of breakers, each column is one 110V phase of the 220. If you can find a breaker in the house and a breaker in the garage on the same column, those should be able to carry the signal.
I do indeed have to columns. I'll see what breakers in the house are on the same side as the plugs in my garage. I never knew this, thanks for the schooling. Its greatly appreciated.