You probably need to search the Electoral Registers.
A quick search brings up Stuart S Wilkinson, Max Wilkinson and Jane C Mansfield living in Newcastle Emlyn in Wales in 2002-2003, 2005,2012 and 2013 - cant see anything obvious for them after that.
So you might need to use something like https://www.192.com/. An initial free search will bring up basic information (as above) but there will be a cost for getting any full address if you find them.