These models are 1:12 Scale.
Included is a Mid-Century Bakelite Plug with three prongs.
Should you wish to add wires, the plugs will fit a 0.6mm wire.
I would highlight recommend an SLA/Resin or Polyjet printer for these models to capture the miniscule details.
If you would like the accompanying wall socket and light switch, these can be found here: https://www.cgtrader.com/3d-print-models/miniatures/other/light-switch-and-wall-plug-sockets-1930s-mid-century-doll-house