Anyone know where I can buy the white tips that go on the end of the pickup selector?

Mine's been loose for a while but stayed on with the help of Blu-Tak but now it's cracked and broken so I need a replacement.

It's a tiny, pretty much superficial flaw but I want my Squire looking its best.

I'm based in the UK so British retailers are recommended.

Thanks guys,
a guitar shop where they sell guitars, pull one from another guitar and put it on yours.
Some companies use a different size hole in the knob. You might try your local shop maybe they have an old switch out of another guitar see if they will part with the knob. SOmetimes stores carry just the knob. Might be worth it to invest in a new switch.
Replace it with a decent switch, and while you are at it, replace the pots and wiring too - Squier electrics are nasty. Best thing I ever did to my Squier Strat(which I still play all the time) was replace the electrics.