Summary

Enclosure for analog panel meter.
Panel meter:
https://www.ebay.com/itm/DC-100V-Analog-Voltmeter-Panel-Pointer-Volt-Voltage-Meter-Gauge-85C1-0-100V-DC/140976223021?hash=item20d2d6732d:g:tJ8AAOxyQyJRkkLk:rk:8:pf:0
Banana plug:
https://www.aliexpress.com/item/Mayitr-10pcs-4mm-Banana-Socket-Nickel-Plated-Binding-Post-Nut-Banana-Plug-Jack-Connector-Red-Black/32817263710.html?spm=a2g0s.9042311.0.0.27424c4dWtsOjQ
Switch:
https://www.aliexpress.com/item/10Pcs-Lot-16mm-Diameter-Small-Round-Boat-Rocker-Switches-Black-2-Pin-ON-OFF-Rocker-Switch/32473122800.html?spm=a2g0s.9042311.0.0.27424c4dOyQFEh