According to this IWM post 1.7 million men served in Britain’s WW2 Home Guard. This latest Home Guard post from Ancestry has 92,037 records for Surrey suggesting it only covers part of the county.
Some registers, linked to the index, have a double page spread with regimental number, name, address, date of enlistment, date of birth, next of kin, religion, national ID number, addedda (notes), and date pt II (a mystery).
Others are much less informative; the search may not find the person. Out of a sample of 500 only 177 transcriptions indicated the location, including 47 for Thornton Heath and 25 for Croydon. More often than not initials rather than first name(s) are given.
Hoping for Hampshire soon…my grandfather served in the Home Guard there as his occupation was a reserved one – he worked at RAE Farnborough.