That being said, a properly connected ground wire should not have enough voltage induced into it to be lighting up anything in most cases.
it is entirely possible that by using an incorrect and potentially unsafe method of testing the original poster may have uncovered a bigger fault in the installation (such as a missing earth to the property.
I would highly recommend that you employ an electrician for a quick safety check of the earthing arrangements.
I would expect an answer within half an hour on site as to the integrity of the earthing system.