Bit of fun in dance for old actor (7,8)

'actor' is the definition.
(I know that Charles Laughton is a actor)

'bit of fun in dance' is the wordplay.
'bit of fun' becomes 'laugh' (I can't justify this - if you can you should believe this answer much more).
'in' means one lot of letters goes inside another.
'dance' becomes 'charleston' (charleston is a kind of dance).
'laugh' placed within 'charleston' is 'CHARLES LAUGHTON'.

'for old' acts as a link.
This may not be correct. Some or all of it may be part of another bit of the clue.

Can you help me to learn more?