Calcutta, July 19 :    Calcutta, July 19:  When should the common door to the first floor of a two-storeyed house be shut at night? The question was enough to trigger trouble and spark gunfire on Swinhoe Street around Thursday midnight. Mithilesh Sinha, 45, a tenant of the Gariahat building, was arrested early on Friday for allegedly opening fire on another tenant during an argument over the closure of a door. Gariahat police said Sinha was involved in 'a heated argument' with Rajesh Sharma, another tenant, and house-owner R. Ray. Suddenly, Sinha whipped out a revolver and fired four rounds. But he was 'inebriated', alleged the police, and so the shots went wild. The house at 4, Swinhoe Street, was built by former chief secretary R.N. Ray and ex-Parliamentarian Renuka Ray. Now, their septuagenarian son, R. Ray, lives alone in one section of the first floor, with the Sinhas and Sharmas occupying the other. Tapas Basu, officer-in-charge, Gariahat police station, said Sinha has an electrical goods shop on Ezra Street, while Sharma has a furniture shop at Mandeville Gardens. The entrance to the first-floor flats of the Sinhas and the Sharmas has a common door. 'One has to enter the door and turn left for Sinha's flat and right towards Sharma's flat,'' Ray said. Trouble was brewing ever since Sinha started eyeing Sharma's section of the first floor, alleged Ray. The retired geologist rejected Sinha's move to take over the other half of the floor. 'Around midnight on Thursday, Rajesh's younger brother knocked on Sinha's door to ask him whether they should close the common door to the first floor,'' recounted Ray. 'Sinha, who was inebriated, slapped the boy and pushed him to the floor. The boy went running back to their room and called Rajesh.' Confronted by the three Sharma brothers, Sinha went on the offensive. After an altercation, he suddenly went into his flat, only to emerge with a licensed revolver. 'He opened fire, but as he was drunk, the bullets crashed into the ceiling and the floor. Nobody was injured,'' Ray said. Officers from Gariahat police station rushed to the house on Ray's SOS.