Brake pad warning coming on with headlights?

I feel a wee bit of background info may (or may not) be helpful with this issue so bare with me... I'll also try to explain as clearly as I can, but feel free to ask any questions.

So...The car has an issue with the brake pad wear sensor connector/wires, so the warning light comes on randomly, then it fixes itself for a while. Its been doing this since about July/August when the front pads were changed. And yes, there's still plenty meat left on them.
The flasher relay has started to be a bit dodgy in the past week. They usually work not too bad, but sometimes they stop, sometimes they flash erratically, as I'm sure a lot of you will know.
I tend to leave the car to warm up for 5 - 10 mins in the morning and before leaving work WITHOUT the headlights switched on. The dash shows the OK after the ignition is switched on and no warning lights after start up either.

Now here's the issue... After getting in the car (keeping in mind that it has already been sat running for 10 mins without any warning lights), I switch on the headlights and up pops the brake pad warning light. Sometimes it doesn't do it, but more often than not it does. Started doing it on Monday and wondered if it could possibly be connected to the dodgy indicator relay in some obscure way?

Any help or suggestions would be greatly appreciated

I'm starting to think I'm on my own with this one...

Posted on two Facebook groups and here, and not one idea or suggestion?
It's not affecting the car in any way, it's just something I rather it didn't do lol.
Only thing I can think is to try fix the pad wear sensor and see what it does. It's just very strange how it's coming on when I switch on the headlights.

I realised it was a case of no one else has had the problem when I wasn't getting any replies. Trust me to have the car that's got a unique problem

I don't mind people guessing, cos it's pretty much what I'm doing. It's a case of any suggestion (or guess) is welcome at this point lol.

The pad warning does come on randomly without the headlights being on, so I don't think it's that.
Will have a poke about it this weekend. May even be something simple like a dodgy battery causing some dodgy signals.

Thanks for the suggestions

Well, it seems to have fixed itself
Still need to fix the issues, but the pad warning has stopped coming on with the headlights... For now at least.. .