What's going on with this junction box?

Post date: 2022-01-24 10:16:34
Views: 254
I removed a ceiling light in my apartment only to discover a junction box with wiring I did not expect. Photo here. Left to right: two-strand white wire; four-strand blue wire; single-strand red wire.

This is an old (late 1960s) apartment building in NYC, and I'm all but certain the box dates to that time. The white and red wires were connected to the old lamp. It's the blue wire that I'm confused by. (All wires had wire nuts before I removed them.) I was hoping to see a green grounding wire, but alas.

So, what's up with the blue wire? Do I need to be calling in an electrician here? Thanks for your advice.
Number of Comments
Please click Here to read the full story.
 
Other Top and Latest Questions:
OpenAI proposes 5% stake to Trump administration to ease Washington pressure: Report
Adjusting clamping pressure on Schuco barrel hinge
Rivian raises 2026 delivery outlook while Lucid misses Wall Street expectations for second quarter
Stargate SG-1: Proving Ground Rewatch
Restrictive immigration policies are changing the composition of the healthcare workforce
Jeff Bezos' family office backed five AI startups in June
How high hopes for Biden’s student-loan forgiveness plans cost borrowers
Ford CEO wants level playing field with Toyota, GM imports as USMCA trade talks reopen
Special Event: 2026 Tour de France
Do Scots men truly correct other Scots men in bar pickups?