<form>
<input type="checkbox" name="item[]" value="1" />
<input type="checkbox" name="item[]" value="2" />
<input type="checkbox" name="item[]" value="3" />
</form>
<?php
$app = JFactory::getApplication();
$items = $_POST['type']; // This works but is not Joomla wise...

$items = $app->input->getArray(array('type_ids')); // Tried multiple ways but can't get it to work.
?>

$items = JRequest::getVar('item', array());

$items = $app->input->get('item', array(), 'ARRAY');

// Get POSTed data
    $data  = $this->input->post->get('jform', array(), 'array');

// Get input object
    $jinput = JFactory::getApplication()->input;

    // Get posted data
    $data  = $jinput->post->get('jform', array(), 'array');

$jinput = JFactory::getApplication()->input;
 $data2  = $jinput->post->getArray(array());
 var_dump($data2);