How to enable/disable Custom Module in magento2

Hi am new to magento 2 and learning how to to create custom modules and i have added a option to enable disable from drop down and also added a config file but that seems to be not working. can anyone help me out.

am sharing my code:-

CONFIG.XML

<?xml version="1.0"?>
<!--
/**
 * Copyright © 2015 Magento. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../Store/etc/config.xsd">
 <default>
     <custom_module>
       <general>
           <enable>0</enable>
              <title>Custom Customer Attribute</title>
         </general>
     </custom_module>
 </default>
</config>

SYESTEM.XML

<?xml version="1.0"?>
<!--
/**
 * Copyright © 2015 Magento. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../Config/etc/system_file.xsd">
    <system>
    <tab id="mytab" translate="label" sortOrder="200">
        <label>Eecom</label>
    </tab>

    <section id="custom_module" translate="label" type="text" sortOrder="300" showInDefault="1" showInWebsite="1" showInStore="1">
        <class>separator-top</class>
        <label>Custom Customer Attribute</label>
        <tab>mytab</tab>
        <resource>Eecom_CustomCustomerAttribute::config_custom_module</resource>
        <group id="general" translate="label" type="text" sortOrder="1" showInDefault="1" showInWebsite="1" showInStore="1">
            <label>General Configuration</label>
            <field id="enable" translate="label" type="select" sortOrder="1" showInDefault="1" showInWebsite="1" showInStore="1">
                <label>Enable Module</label>
                <source_model>MagentoConfigModelConfigSourceYesno</source_model>
            </field> 
        </group>
  </section>
</system>
</config>

Helper/Data.php

<?php
/**
 * Copyright © 2015 Eecom . All rights reserved.
 */
namespace EecomCustomCustomerAttributeHelper;
class Data extends MagentoFrameworkAppHelperAbstractHelper
{

    /**
     * @param MagentoFrameworkAppHelperContext $context
     */
    public function __construct(MagentoFrameworkAppHelperContext $context
    ) {
        parent::__construct($context);
    }

    public function isEnabled()
{
    return (boolean) $this->getConfig('eecom_customcustomerattribute/general/enable');
}
}