Custom fields in ticket email
That should definitely be possible. In the first instance, please do check out our Themer’s Guide for a high level overview of setting up template overrides:
In this case specifically, you’ll probably want to make a copy of event-tickets/src/views/tickets/email.php and place that copy in YOUR_THEME/tribe-events/tickets/email.php – you can then safely modify the ticket email.
If you look inside that, you’ll see that there is a line of code looking like this:
$event = get_post( $ticket['event_id'] );
At any point after that, you can therefore access the event and the event’s post ID – and can use that to pull in data from any custom fields you have created, something like this:
$address = get_post_meta( $event->ID, '_hidden_address_field', true );
Simply echo or print this data at a suitable point in the flow of the email. Does that help at all?