Checkbox

<?php

$tea_content = array(
    array(
        'type' => 'checkbox',
        'title' => 'What are your preferred personas?',
        'id' => 'my_checkbox_field_id',
        'default' => array('minions', 'lapinscretins'), //define the default choice(s)
        'description' => '',

        //define your options
        'options' => array(
            'minions' => 'The Minions', //value => label
            'lapinscretins' => 'The Lapins Crétins',
            'marvel' => 'All Marvel Superheroes',
            'franklin' => 'Franklin (everything is possible)',
            'spongebob' => 'Spongebob (nothing to say... Love it!)',
        ),
    ),
);

Retrieve data

Using the _get_option('my_checkbox_field_id') method, you'll get (with a json_encode() display):

{
    "minions": "minions",
    "lapinscretins": "lapinscretins"
}