Well, as usual there are many ways to do it but one way would be using the
GetField snippet this way :
[tt][!GetField? &docid=`5` &field=`content`!][/tt]
You can get any TV for any document with getfield you could have used :
[tt][!GetField? &docid=`5` &field=`alias`!]
[!GetField? &docid=`8` &field=`pagetitle`!]
or [!GetField? &docid=`13` &field=`my_template_variable`!][/tt]
This being said, it would seem that it’s not necessarily what you need to do here, contrary to what your title implies.
It would seem you want to re-use content rather than call content from one page to another.
In you case, if you need to re-use the contact form, just place the form in a chunk and then insert that same chunk everywhere you need it
Every time you edit the chunk all the pages including it will be updated.
