How to wire a digital LED voltmeter in line with an illuminated rocker switch so the switch light is on and the meter displays the actual voltage
You don't wire a voltmeter in series with the load. Instead you wire it in parallel with the load because you're trying to measure the voltage across the load.



simulate this circuit &ndash; Schematic created using CircuitLab
Figure 1. A voltmeter is wired across the load. An ammeter is wired in series with the load.