Ticker shown by doctor on box, holding pen (10)

I believe the answer is:

watchhouse

I'm a little stuck... Click here to teach me more about this clue!

'box holding pen' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.

'ticker shown by doctor' is the wordplay.
'ticker' becomes 'watch' (synonyms).
'shown by' says to put letters next to each other.
'doctor' becomes 'house' (I am not sure about this - if you are sure you should believe this answer much more).
'watch'+'house'='WATCHHOUSE'

'on' is the link.

Can you help me to learn more?

I've seen this clue in the Sydney Morning Herald.

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