my $f0="%-22s %s\n"; 
my $f1='%-22s'             .$f0; 
my $f2='    %-18s'         .$f0; 
my $f3='        %-14s'     .$f0;
my $f4='            %-10s' .$f0;

sub printList {
    my $self = shift;
    my $fh = shift;

    foreach my $struct (sort values %{$self->list}) {
        my $type = $struct->type;
        if ( $type =~ /LIGHT|FAN|CAMERA|CHRISTMAS/ ) {
            printf $fh $f4, $type,$struct->name,$struct->hu;
        }
        else{ 
          my ($ftop,$fline); 
          if ( $type =~ /ZONE/ )  { $ftop=$f1; $fline=$f2;} 
          if ( $type =~ /GROUP/ ) { $ftop=$f2; $fline=$f3;} 
          if ( $type =~ /AREA/ )  { $ftop=$f3; $fline=$f4;} 
          printSet($struct,$fh,$ftop,$fline); 
          printList($struct,$fh);
        }

    }
}

sub printSet  { 
  my $struct=shift; 
  my $fh=shift; 
  my $ftop=shift; 
  my $fline=shift; 
  $name = $struct->name;

  printf $fh $ftop, $struct->type,$name,$struct->hu; 
  for my $method (qw/security state battery/) { printf $fh $fline,uc($
+method),$name,$struct->$method; } 
} 

sub printConfig {

    my $configfile = shift;
    my $house = shift;
    my $space = "";

    open(my $fh, ">$configfile");
    printSet($house,$fh,$f1,$f2); 
    printList($house,$fh,$house->type);

    close($fh);
}
[download]

Of most interest here is that "methods" are nothing but string literals.