How to set a string length on wysiwyg text? (Wordpress)

Question

Is it possible to cut the length of a string in the wysiwyg editor? I have set up some custom post types and on the archive page I want to be able to set a string length limit, if that limit is reached I also want to add ... to the end of it. Some of these posts have multiple paragraphs incase thats an issue.

I have tried many solutions like the following that don't work;

<?php echo mb_strimwidth( get_field('event_information'), 0, 10, '…'); ?>

Answer 1

I've used this before:

<p class="excerpt">
  <?php $customexerpt = get_the_content(); echo wp_trim_words( $customexerpt , '15' ); ?>
</p> 

But using the excerpt field is probably recomended.