JimboZA:
For what it's worth, this Wikipedia article says it's good for .577 A per conductor and 125VDC. Seems there are 8 conductors per wire so that gives you under 5A per wire; your 7A is asking for trouble.
And since the peak value of a 120VAC sine wave is around 170V, the answer to the original question should be abundantly clear.
Too often on this forum we are presented with a solution rather than a problem, and asked, "Will it work?" Not only can this be difficult to answer without knowing the problem, but it precludes alternate suggestions that may represent improvements on the original "solution".
In this case the answer is clear: Yes, this could very well cause a fire as the cable is clearly being operated beyond its specifications, relative to both current and voltage.
At the risk of sounding like a broken record (remember records?), I will ask again: Why do you want to do this?