this is how the story goes:

At about 10 years ago,after joining this company ,i was asign to one construction site(sorry for not saying the building name),as a site supervisor to look after the building's project,due to the handover dead line is near,so everybody need to work round the clock inorder to meet the timing.At about 2am in the morning ,my friend ,(work as a safety supervisor)come to 12th floor to find me for a coffee, due to the lift is not ready to operate, so we walk down by stair case ,when we reach 5th floor,we heard a knocking sound coming from a room whereby this room is already handover and there should be nobody is allow to enter this room ,only the management and the safety has the key to enter.Out of curiousity,my friend take his key ,open the door to find out what's going on,after that we saw a indian worker busy knocking the floor with his hammer,so we approch him and question him why u are here whereby nobody is allow to enter this room,and he just busy working and mumbering says:boss call working ,no rest ,no rest,than suddenly he stand up and walk away and disappear into the thin air with an acore saying:no rest,no rest,than me and my friend was so shock and quickly ran out without locking the door and dash to the ground floor,that night we do not even dare to go back to this building.