In my home cash game ( 1-2 no limit holdem ) .

When one or more players are "all in" dealer usually asks the players
in the hand to turn over their cards before we deal out the board. We
of course all want to watch the race to see who has what and which
hand eventually wins.

Several players have stated that in a cash game you do not have to turn
your cards face up. Obviously you need to show both of your cards to
win the pot, but the losing hand just throws his cards away and no one
will ever know what that players cards were.

Is it up to the house, do rules state a player need not show his hand during
the race?

Well??