Police who raided a flat above a barber's shop in Liscard found a cannabis factory with a crop worth £43,000, a court heard.
Officers found the three rooms had been converted in a sophisticated operation with an array of specialised growing equipment installed.
Police attended at the premises in Liscard Road on January 10 after smelling cannabis.
When they called, curtains were seen moving, but after their forcing their way in, there was nobody there, said Kim Egerton, prosecuting.
As well as 54 cannabis plants they discovered 32 high-intensity lighting units, 21 transformers, two air pumps and two carbon filters.
A fingerprint on a timer box led to the arrest of pub manager Richard McDonough, who admitted helping set up the equipment for £50 a day for a man he knew.
47-year-old McDonough, of Croft Close, Prenton, pleaded guilty at Liverpool Crown Court to producing cannabis.
Sentencing him to 14 months' imprisonment suspended for two years, Judge Robert Warnock queried: "What on earth did you think you were getting into?"
He pointed out he has serious responsibility in the licensed victuallers trade as he now manages three pubs and also has a young daughter.
McDonough was also ordered to carry out 240 hours of unpaid work and to pay £350 prosecution costs.
Gerald Pachter, defending, said McDonough has no previous convictions for drugs offences and does not use them. He admitted in interview: "I'm stupid, I have done wrong."
He had had massive debts, perhaps linked to illness, and had been asked to helped set up the equipment.
But had not realised the extent of the operation. He had made a total of £400 after being approached to help.
Mr Pachter said his client was now turning his life around and his debts are under control: "He greatly regrets what he has done," he said.