Stuck with a Custom Field Check box Array

It’s a serialized string. Use Unserialize to get an array out of this. Also checkout WP’s maybe_unserialize method.

<?php $string = "s:19.a:1:{i:0;s2";

//Using WP maybe_unserialize
$result1 = maybe_unserialize($string);

//Using PHP unserialize
$result2 = unserialize($string); 

echo "<pre>";
print_r($result1);
print_r($result2)
echo "</pre>";
?>

$result will hold what you want.