B737-700
Time Pressure; Communication Breakdown
Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Security; Deviation / Discrepancy - Procedural Weight And Balance
Procedure
Ops agent had given me the count as 47+1 and was ready to close the door. I asked him to wait so that the C Flight Attendant (FA) could finish briefing the exit row. Something either I (the A) or the C said alerted one of the passengers in the exit row; and she asked us if she was on the correct flight to ZZZ. We informed her that no; we were going to ZZZ1. That is when she grabbed her things and deplaned. I asked him what the new count was and he said; 'Now it should be correct.' My thing is; there's no way to cross check the passengers count; and if that 'extra person' had been a terrorist; we could have been in serious trouble. We had no way of knowing that an extra person was on there; and if she hadn't been in the exit row; she might not have known herself.
B737-700 Flight Attendant reported a security issue with inaccurate passenger count procedure.