### Summary

If a module calls `fail_json()` and provides `exception=None`, this will crash every callback that uses `_handle_exception` from `CallbackBase`: if verbosity is < 3, it will try to call `split` on `None`, and otherwise it will try to concatenate a string with `None` (which results in `TypeError`).

### Issue Type

Bug Report

### Component Name

lib/ansible/plugins/callback/__init__.py

### Ansible Version

```console
devel
```


### Configuration

```console
*
```


### OS / Environment

*

### Steps to Reproduce

*

### Expected Results

*

### Actual Results

```console
*
```


### Code of Conduct

- [X] I agree to follow the Ansible Code of Conduct
''' retrieves the value to be displayed as a label for an item entry from a result object'''
        if result.get('_ansible_no_log', False):
            item = "(censored due to no_log)"
        else:
            item = result.get('_ansible_item_label', result.get('item'))
        return item
    def _process_items(self, result):