Lights staying on with sensors

[lockhes]

Went to look at some lights today as they were not working turns out all the problem was is bulbs swapped and away I go These lights are on pir sensors as it's a communal walkway to flats just got a phone call to say there on all the time Any ideas why Paul

 

[dcelectrical]

1 possible rectification of this is that sensors are in override,
with most sensors if you turn them on and off three times the third time you turn them on they turn into permanantly on mode
to reset this you can turn them off for a minute and then turn them on again (usually via the mcb) they will usually settle down, after that it get complicated with covering the sensor etc.
good luck