You have the mains L and N going into the bridge and one output of it goes to earth. This will blow the mains fuse or trip the earth leakage breaker. The COM or earth of the electronics must be left floating, which means the whole circuit cannot be connected to any earthed piece of equipment. If your monostable delivers a short pulse you can feed it through a pulse transformer or an optoisolator to the next circuit, BUT all the preceeding circuit must be properly insulated, because the L and N of the mains may be interchanged.
Frank