use strict;
use warnings;

my @final_array=qw/test1 test2 fred/;
my $regexp = "(" . join("|", @final_array) . ")";

while(<DATA>){
  s/$regexp/pagingRAC/g; 
  print $_;
}

__DATA__
this is a test
this line contains test1 and test2
fred bassett is a dog but I can't spell his name.