55 Gmc series 2.

I've been having problems with the brake lights not working, found it was the wires that connect to the brake light switch. I've tried everything to secure them better to no avail. Anyone have any recommendations on this or know if there are specific fasteners to use?

Here is the switch:

http://www.classicindustries.com/images/productimg/t/t70850.jpg


1955 GMC 100 Series 2