Hi Paul. Recommend you do not use your shower untill a competant person has looked at it. Water should never appear from within the casing. If its under waranty best sort it that way. Turn it off till its fixed !
Possible cause of leak could be a fractured component due to excessive system pressure which sometimes builds up during the night. A lot of new properties have water meters which have non return valves inside . This traps the water . When the water expands where does it go ! if its got nowhere to go it will burst something . Usually your shower. Please dont use it till its fixed !
Alan
December 2008