People may wrongly believe this Burnham ground hosts Sunday cricket finals (5,4)
I believe the answer is:
urban myth
'people may wrongly believe' is the definition.
I don't know anything about this answer so I cannot judge whether this works.
'burnham ground hosts sunday cricket finals' is the wordplay.
'ground' indicates an anagram ('grind' the letters into a new form).
'hosts' means one lot of letters goes inside another (inserted letters are welcomed or hosted).
'finals' suggests the final letters (the final letters).
The last letters of 'sunday cricket' are 'yt'.
'burnham' anagrammed gives 'urbanmh'.
'urbanmh' placed around 'yt' is 'URBAN MYTH'.
'this' is the link.
Can you help me to learn more?
(Other definitions for urban myth that I've seen before include "Very plausible but untrue story" , "Legend - 1 8 across?" , "yarn given an unlikely twist" .)