Elevators: One symptom of decline of a defective terrain

Elevators:  One symptom of decline of a defective terrain

Yesterday at one point I saw Passenger Elevator 5's (PE5) floor indicator light in the lobby blinking 16.  Then later saw the Service Elevator light blinking 16.  I have also heard the high pitched ringing when at the elevators waiting to go down though not sure what floor that was taking place more than once.