on/of switch for an outdoor light

Hard to understand the question. If you can switch it on then the inverse must be that it was off to start with? Need some more details to help you properly. Update. I see it's a sensor light. There will be a switched live and permanent live supplying the light. It's hard to tell from what you've described as to how the light is isolated. If your able to look up the make and model of the light you may find it could even have a manual mode that is initiated by a pattern of toggling the light switch. I won't be able to offer specific instructions on how to rewire this light for you unfortunately. I can tell you that it can be done though! You'd could ask more in depth on a diy or electrical forum. This website isn't a good format for offering explicit instruction. If you have any doubts its always best to use a registered electrician. Cheers. S

It appears that the switch you have is an override switch, meaning it overrides the PIR making the light permanently on when the switch is in the on position and when the switch is in the off position the light shall be controlled via the PIR. Depending on how it has been wired will depend if you can have the switch that controls the on/off of the light. But I’d imagine it’s a small modification.

You need a 3 stage switch. Middle would allow it work on PIR (sensor). Down would be override ON. Up would be override OFF.

So you have a permanent feed to the pir, and a switched live override. If I understand you correctly you want this switch to switch the light off completely? May need to be required if all they’ve done is dropped a switch pair down from light to switch. Not a big job