1) Add “Hover” attribute

Go to Stores > Attributes > Products and click on “Add New Attribute”

Create the attribute “Hover” and Select “Media Image” in the “Catalog Input

Type for Store Owner” dropdown and Save it.

2) Now go to Attribute Set.

Stores > Attributes > Attribute Set

Add “hover” attribute to “Images” Group like the below screenshot.

3) Now go to product and upload an image and select Hover like below screenshot.

4) Now we have to use this attribute in the listing page. So we have to make ‘used_in_product_listing’ to 1.

We can do that by using MySQL.
You need to take “hover” Attribute_ID from admin.
You can go to your “hover” attribute page in admin and get its ID from URL.
Suppose that Attribute_ID is 99 in our case.
Now, go to the database and select the “catalog_eav_attribute” table.
Select the attribute with id 99 and change the value of the `used_in_product_listing` column to 1.
Use below MySQL query :

UPDATE catalog_eav_attribute SET used_in_product_listing = ‘1’ WHERE attribute_id = 99;

5) Declare Hover attribute in view.xml
view.xml should be in app/design/frontend/MyThemeVendor/MyTheme/etc/view.xml

add below code

<?xml version="1.0"?>
 <view xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Catalog:etc/view.xsd">
 <media>
  <images module="Magento_Catalog">
   <image id="hover_product_list" type="hover">
    <width>240</width>
    <height>300</height>
   </image>
  </images>
 </media>
</view>

6) Get “Hover” attribute in listing template

Listing template is in app/design/frontend/MyThemeVendor/MyTheme/Magento_Catalog/templates/product/list.phtml

User below helper to initialize hover image.

<?php 
$_imageHelper = $this->helper('MagentoCatalogHelperImage');
$_imageHover = 'hover_product_list';
?>

Search “product-image” class and use the below code and CSS to get a hover image.

<div class="product-image">
    <div class="product-label">
        <?php 
            $newFromDate = $_product->getNewsFromDate();
            $newToDate = $_product->getNewsToDate(); 
            $now = date("Y-m-d H:m:s");
            // Get the Special Price
            $specialprice = $_product->getSpecialPrice(); 
            // Get the Special Price FROM date
            $specialPriceFromDate = $_product->getSpecialFromDate();
            // Get the Special Price TO date
            $specialPriceToDate = $_product->getSpecialToDate();
        ?>
        <?php if($specialprice && (($specialPriceFromDate <= $now && $specialPriceToDate >= $now) || (($specialPriceFromDate <= $now && $specialPriceFromDate != NULL) && $specialPriceToDate  == ''))): ?>
            <span class="sale"><?php echo __('Wras'); ?></span>
        <?php endif; ?>                        
        <?php if((($newFromDate <= $now && $newToDate >= $now) || (($newFromDate <= $now && $newFromDate != NULL) && $newToDate == NULL))): ?>
            <span class="new"><?php echo __('New'); ?></span>
        <?php endif; ?>
    </div>
    <div class="product-item-image" data-container="product-grid">
        <?php
            $productImage = $block->getImage($_product, $imageDisplayArea);
            if ($pos != null) {
                $position = ' style="left:' . $productImage->getWidth() . 'px;'
                    . 'top:' . $productImage->getHeight() . 'px;"';
            }
        ?>
        <?php // Product Image ?>
        <a class="product-item-photo-focus" href="<?= $block->escapeUrl($_product->getProductUrl()) ?>">
            <?= $productImage->toHtml() ?>
        </a>
        <?php //Product Image Hovered ?>
        <?php
        $productImageHover = $_imageHelper->init($_product, $_imageHover);
        if ($pos != null) {
            $position = ' style="left:' . $productImage->getWidth() . 'px;'
        . 'top:' . $productImage->getHeight() . 'px;"';
        }
        ?>
        <?php if (strpos($productImageHover->getUrl(), 'Magento_Catalog/images/product/placeholder/hover.jpg') == false) { ?>
            <a href="<?php /* @escapeNotVerified */ echo $_product->getProductUrl() ?>" class="product-item-photo-hovered" tabindex="-1">
                <img src="<?php echo $productImageHover->getUrl(); ?>" class="photo-image-hover" width="<?php echo $productImage->getWidth(); ?>" height="<?php echo $productImage->getWidth() ?>" alt="<?php echo $productImageHover->getLabel() ?>"/>
            </a>
        <?php } ?>
    </div>
</div>

CSS:

.product-item-image {position: relative;}
.product-item-image:hover .product-item-photo-hovered {opacity:1;z-index: 1;visibility: visible;}
.product-item-photo-hovered {position: absolute;top: 0;left: 0;visibility: hidden;opacity: 0;transition: 0.6s;}