Class not found error with events

I'm migrating a CI3 app to CI4, so naturally that means converting the hooks to events.

I have the following in app/Config/Events.php:

PHP Code:

Events::on('post_controller_constructor', ['Load_config', 'load_config']); 


In app/Events/Load_config.php I have:

PHP Code:

<?php

namespace App\Events;

use app\Libraries\MY_Migration;
use app\Models\Appconfig;
use CodeIgniter\Session\Session;
use Config\Services;

/**
 * @property my_migration migration;
 * @property session session;
 * @property appconfig appconfig;
 * @property mixed $migration_config
 * @property mixed $config
 */
class Load_config
{
    /**
     * Loads configuration from database into App CI config and then applies those settings
     */
    public function load_config()
    {
.
.
. 


But when I load the application I'm greeted with "Error Class 'Load_config' not found". I'm assuming that this means that the event loader is not looking where I'm expecting it to look. A couple of questions come up:
- Where should classes formerly in the hooks folder be kept?
- Am I missing a reference in my event call that would cause the event loader to look in app/Events/ to find the class? I thought namespacing the class would take care of that, but perhaps I'm mistaken.