What visitor at doorstep might do to sound familiar (4,1,4)
I believe the answer is:
ring a bell
'sound familiar' is the definition.
(I've seen this before)
'what visitor at doorstep might do' is the wordplay.
I cannot quite understand how this works, but
'at' could be 'in' and 'in' is located in the answer.
This explanation may well be incorrect...
'to' acts as a link.
Can you help me to learn more?
(Other definitions for ring a bell that I've seen before include "Formally declare (appointment)" , "Signal to start class" , "Town crier may" , "Advice to cyclist" , "to remind one of something" .)