This model is a plug to be used on a patio light stringer to fill an empty socket. This will give a set of light stings a much more finished appearance, will prevent debris from accumulating in the sockets, and will prevent accidental shorting of the contacts.
The socket is a standard E26 socket and the length is sized to fit a S14 bulb, common on patio string lights.
This was printed using PETG with a .6mm nozzle, but the design should be flexible for almost any nozzle size and material. Just ensure no material with metal additives is used that could provide a low resistance path across the contacts.
The original design of the threaded portion was based on an existing model at thingverse by toybuilder (https://www.thingiverse.com/thing:129908)
The author hasn't provided the model origin yet.