Measure the number of aunts and uncles per house! (8,7)

'measure' is the definition.
The answer and definition can be both human attributes as well as being singular nouns.
Maybe they are linked in a way I don't understand?

'the number of aunts and uncles per house' is the wordplay.
I cannot really see how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is located in the answer.
'number' could be 'iv' (IV is an example) and 'iv' is present in the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is located in the answer.
'per' could be 'a' and 'a' is located in the answer.
This may be the basis of clue (or it may be nonsense).

Can you help me to learn more?