Please consider the following things.
For example:
if your attribute is banner_gral
Then in your controller saveAction() when saving the checkbox data do
$banner_gral = isset($your_form_Data['banner_gral']) ? 1 : 0;
For Grid and Form Page
In your controller you should have Mage::register(...)->getData() or Mage::register(...)
public function editAction()
....
Mage::register('example_data', $model);
On your form _prepareForm()
$model = Mage::registry('example_data'); // NOTE registry('example_data'); NOT registry('example_data')->getData();
$fieldset->addField('entire_range', 'checkbox', array(
....
'checked' => $model->getBannerGral()==1 ? 'true' : 'false',
......
))
On your grid _prepareColumns()
$this->addColumn('banner_gral', array(
....
'type' => 'checkbox',
'index' => 'banner_gral',
'values' => array(1,2),
'field_name' => 'checkbox_name',
....
));