If metal moves in a magnetic field It creates a current so when the ISS or any other satellite/object charged so that if you connected a light/ put it in a circuit/ it would light up? also why doesn't this have an effect on electronics on earth.
Charging, as nibot said, happens because the "balance of charge" is altered. If you have a neutral ISS, and you assume that no electrons are added or removed, the ISS will stay neutral. This can of course change, and the ISS can charge, if electrons are removed or added due to the exposure to ionizing radiations.
However, you are right to say that if a metal moves in a magnetic field, you obtain a charge separation, and consequently a voltage. The same concept is used in any dynamo to produce electricity. There was indeed an experiment using this concept:
It was deployed twice with little success, but it did produce a (small) voltage, and therefore create a current.
Well, it probably is charged, as it continuously exposed to all sorts of radiation (including charged particles) from the sun and elsewhere. The fact that it is made of metal and moving through a magnetic field is not a source of charging, however. The principle of magnetic induction says that a conductor moving through a magnetic field will develop a voltage across it. A changing magnetic field will induce eddy currents in the metal shell of the spacecraft which will result in some heating and will also produce magnetic fields. Managing the effects of radiation, charging, and torques introduced from magnetic fields are all important parts of spacecraft engineering.
Could you hook up giant wires to the ISS to make it into a giant generator as it spins through the earth's magnetic field? Maybe, though the back-action would cause the orbit to decay faster than it usually does.