Thank you for your help the 1881 Census is the right Gaffney Family they did come back from USA and William was born in Liverpool but went back to the USA when an Adult, the paper I found a William Gaffney in was http://cdsun.library.cornell.edu/cgi-bin/cornell?a=d&d=CDS19171010.2.45.3# the Act was Called"The Four Entertainers," a vaudeville act consisting of Lloyd A. Bailliet, Will- iam Renaud, William Gaffney and Jack. Shannon, This was from 1917 :-)
The last census we can see in the US is 1940 and there is a William Gaffney living as a boarder in Wayne, Detroit with a family named Doylee but is doesn't give his occupation - not surprising as he is 70 years old so no doubt retired.
The only thing I can suggest is that you google for theatrical information/agents and make enquiries as to any records that might be held for the period you are looking at.
Linking people up to random bits of information is always going to be very difficult unless you have some other clues.
I also suggest to start a family tree for the Gaffney name and fill in as much detail as you can which can give 'sideways' clues to the person you are looking at such as another relative living in the US.
Margaret