Side lights n rear fogs blowing fuses, please advise

Left hands side Side light and also rear fog lights fuses blow.

Anybody advise on what I should check?

Te background to this is -

The other week my rear foglights were coming on automatically when I out my side lights on...weird.
I thoguht maybe a problem with the switch, but no joy.

Then all of a sudden the went out and did not come on at all even when my headlights were on and foglight button pressed.

It noticed that my left hands side side lights were out, front and rear.

I checked the fuse box to find that the fuse had blown and also the fuse for the rear foglights had blown.

I replaced them but as soon as I switched my side lights on, the fuse went and same for the foglights, soon as I preseed the button to turn them on, I heard the fuse POP.

Any advice on where I should start looking.

Any pointers would be greatly appreciated.

Thanks

Sounds like a wiring short to me. Take rear light units out and check them over for corrosion.