Cleaning Old Hardwood Floor
First go get a lead test kit and use it , I have found lead in pre 1964 shellac . a completely wrung out towel and some dish soap , If you are going to refinish .You don't want wax impurities to contaminate the future finish . Or a little paint thinner , But use this moderatly and keep and eye on whats rubbung off .If it is wax then you may scub the wax finish off .
I could already be a wax finish , In that case lacquer will rub some off fairly quickly . tacomahardwoodfloors.com