I saw a cart today that said 76 in 1 on it. It was black, about the size of a Genesis cart or like a cart that would go in the Saturn, and it had a number of pictures of different games on it. It said 76 in 1, and had some japanese writing.
I'm assuming that it's one of those pirate carts, and that it might work in a Famicom, but it wasn't the shape of a NES cart, so I'm not sure exactly what it was.
Anyways, the dude wanted $30 for it, and wouldn't budge, so I passed.