According to a reply in https://sharepoint.stackexchange.com/questions/67900/updating-a-wiki-page-with-the-rest-api , I can get a Wiki page's content by extracting the WikiField field from the response of
GET https://<site-url>/_api/Lists(guid'<list-id>')/Items(<item-id>)
I expected the output to be the same as the Wiki Content field when editing the item (View All Pages > click on wiki page > Properties > Edit All). But in the REST API response, the link [[Home]] gets
replaced by a <a> link,
and the escaped \[[Home\]] is
unescaped to [[Home]].
How do I get the WikiField's value in the expected format?