How to remove a fieldset from around a Mailchimp Subscription field? I have added a Mailchimp Subscription field to an entity form using the Mailchimp module. I'm having difficulty in removing the fieldset around this subscription field.

I have installed the Devel module and used the dpm function to display info on the form. But I can't seem to find what theme function I need to override to remove the fieldset. 

I have an existing form alter applied to this form, what would I need to add to my existing form alter to remove the fieldset around the field?
You need to use YOURTHEME_form_alter of YOURMODULE_form_alter https://api.drupal.org/api/drupal/modules%21system%21system.api.php/function/hook_form_alter/7

there you can alter that form. dpm or print_r $form and see where that fieldset is defined and you can unset it

you will see something like

array( 
   'some_field' = array(
    '#title' = 'some title',
    '#type' = 'fieldset',
  )
)


then you can do

unset($form['some_field']['#type'])


that should do the job