Make conductor-testing a hands-on hunt and model series vs parallel with the whole class.
Conductor hunt
Beyond the supplied test materials, send students on a quick "conductor hunt" around the room with their test circuit, predicting then testing everyday objects (a door key, a pencil, a shoe). Physically touching the probes to each object and watching the globe makes the conductor/insulator split tangible — keep the test fair by using the same circuit each time.
Human series vs parallel
Model the two circuit types with bodies. Series: students in one loop, each a globe; "remove" one student (a break) and the whole loop goes dark. Parallel: students in two side-by-side branches from the same cell; remove one branch and the other stays lit. Feeling one break kill a series loop but not a parallel one is the key insight.