What is this thing with a bulb

[offiedk]

What is this white thing it has a wire with bulb going to one off the instrument lamps in the dash.
It looks kinda aftermarket.
Chevrolet c10 1974

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[Strick]

Probably for the wiper switch illumination. The pic isn't the best so it's hard to tell.

HS

 

[offiedk]

Probably for the wiper switch illumination. The pic isn't the best so it's hard to tell.

HS

Found out that wire is a optical fiber leading the light from the cluster, never seen that before

 

[xm20k]

Probably a home DIY due to no light in the early switch or a bad/defective unit, I don't remember whether they had a built-in light early on or not.

 

[Snoots]

That's stock GM.

 

[75gmck25]

Stock light (despite its very unusual look) for the wiper switch illumination.