Fasterner-brige connectors
Paper fasteners allow to cramp on metal legs from resistors, diodes and other electronic components. They are very useful to create a small ad-hoc circuit involving resistors or LEDs.
You can also use paper fasteners to hide connections under the cardboard as described in this instructable
Make
Step 1: punch the cardboard
Use a hole puncher and very carefully scissors to punch a hole for the paper fasterner.
Step 2: connect the cables
Slide the cables in between the legs of the fasterner and secure it in the hole
Step 3: complete the circuit
Complete the circuit with a binder clip or another faster!