I'd prefer a hands-on test, but for test questions for residential:
1) A 12/3, two 12/2 cables, and a device are in a clampless box rated 22in
3. All cables have a wire EGC. Is this allowed by the NEC? Explain your answer.
2) When replacing 2 prong receptacles, what are the options?
3) Describe in 50 words or fewer how you would cut in a new box for a receptacle in a plaster wall.
4) What are the most important things in customer service?
5) What section is most applicable to non-metallic cable?
6) Name at least 4 places GFCI protection is required
7) Do you have any conditions that would limit or prevent you from working in crawlspaces or attics?
8 ) How many 12ga wires are typically allowed in a red wire nut?
9) What safety precautions would you take when adding a new circuit to a 240V single phase panel?
10) How often must NM cable be supported?
11) What is the purpose of grounding?
12) What is the purpose of bonding?
13) What is a MWBC?
14) A residential customer calls reporting a fried TV. You arrive and find that the panel leg #1 has 155V, and leg #2 has 85V. What is the most likely cause?
15) When wiring a new HVAC unit with the nameplate specs of 12A MCA and 30A MOCP, what sized wire and breakers would you use?
16) A residential customer calls reporting flickering incandescent lights in one room only. What steps would you take to troubleshoot this problem?
17) How many amps does it take to stop your heart?
18) What is the maximum allowable distance for boxes to be set back from the surface of drywall? From wooden paneling?
19) Explain in 20 words or less how GFCI receptacles and breakers work.
20) What if anything is incorrect about using 3 NM cables in an underground raceway to feed a detached garage?
Hands-on:
1) Demonstrate how to wire a GFCI receptacle so that it affords downstream protection.
2) A clampless single gang box of 20in
3 has 5 14/2 NM w/o ground cables in it. Explain/demonstrate how you would correct this.
3) Properly wire a single-pole AFCI breaker.
and oops, 4. I claim typo.
Depends on the level of help you wish to hire as well. Someone green but willing to learn and do may very well do horribly on test but if you're willing to train them, they may be an outstanding employee.