Hi Sharon K
1851: Temperance Street, Merthyr Tydfil
HO107 / Piece 2458 / Folio 373 / Pg35
Head: Jonah WILLIAMS 36, Carp'tr, b Llanfihangel, Carmarthenshire,
Wife: Elizabeth WILLIAMS 36, Llangan, Carmarthenshire
Son: David WILLIAMS 11, Scholar, Llanganrae, Carmarthenshire
Lodger: Elizabeth BARRETT 24, Llan----o?, Carmarthenshire,
Lodger: John PRICE 25, Labourer, b Kerry, Montgomeryshire
Is the census attributed to your John PRiCE by fellow Rootschatter Wendy Mc back in 2005 (she hasn't been active on Rootschat since 2006 though).
The residence address on a marriage cert may not refer to where he was lodging immediately prior to marriage.
Cheers
AMBLY