Who knows companys or places who need cleaning service?

OK. MY DAD HAS HIS OWN CLEANING COMPANY AND HES A GRATE WORKER HES TRYING TO FIND MORE JOBS... HE DOSE ALL TYPES OF CLEANING.... WHO KNOWS COMPANYS OR PLACES WHERE THEY NEED SOMEONE TO CLEAN? OR HOW CAN I FIND PPL THAT NEED A COMPANY TO CLEAN FOR THEM? AROUND CHICAGO! PLEASE LEAVE THEIR ADRESS OR PHONE ECT.