Why Is There a Light Bulb in There?
April 2, 2025
Source: Reddit
So, here’s a weird one for you: I found a tiny lightbulb inside a little wall cabinet near the stairs in our 1923 Oregon home. It turns out this was once a 1920s Milk Door.
It wasn’t labeled. No instructions. Just a dusty bulb—about the size of a ping pong ball—mounted inside this shallow wooden cubby behind a small door. The kind of thing you might walk past a hundred times without noticing. It turns out it might have been part of a 1920s Milk Door.
I finally opened it out of pure curiosity, expecting a fuse box or maybe an abandoned mouse hotel. Instead, I got a quirky little mystery. Naturally, I taped a drawing of a hot air balloon inside (for my daughter, but also maybe a little for me).
Anyway, once I got over the “huh, that’s odd” stage, I started trying to figure out what this thing actually was.
The Milk Door Theory (Most Likely)
After some digging, it turns out this was probably a 1920s milk door.
Back in the day, homes often had small pass-through cabinets built into exterior walls so the milkman (or sometimes grocers) could drop off daily essentials—milk, butter, eggs—without knocking or coming inside. You’d open the inside door, grab your delivery, and go about your day.
Simple. Efficient. No need to change out of your robe.
Some of these had little light fixtures inside—just like the one I found—to help homeowners see what was delivered in the early morning or gloomy winter evenings. In some cases, the light even served as a signal: if it was on, there was something inside the 1920s Milk Door.
But Wait—Could It Be Something Else?
Here’s the fun part. As I kept poking around and talking to old-home nerds (bless them), I found out there are a few possible reasons a light like this might exist in a wall cabinet like mine:
- Delivery Door (Milk Door) – This is still the best guess. Everything lines up—the location, the wiring, the shallow depth, and the bulb size. It matches what you’d expect from a 1920s Milk Door.
- Utility Lighting – It might’ve just been a basic light installed to help illuminate a dark corner of the stairwell or a small crawlspace nearby. Old houses didn’t always have generous lighting plans.
- Call System or Service Indicator – In fancier homes, lights like this were part of a buzzer system. Press a button in one room, a light goes on in another. Ours isn’t quite that fancy, but who knows?
- Miniature Heating Space – Okay, this one blew my mind a bit. Some old cabinets had small bulbs installed specifically to generate heat. Not much, but just enough to prevent medicine, shaving cream, or even certain toiletries from freezing in the winter—especially if the cabinet was on an exterior wall. If your bathroom’s ever had a toasty “shaving cabinet,” you know the vibe.
Honestly, the heating theory doesn’t sound too far-fetched. The cabinet is tiny, enclosed, and tucked into a wall near the stairs—maybe it was used to keep something from getting too chilly.
So… What Do I Use It For Now?
Mostly? A conversation starter. Oh, and an art gallery for a very colorful hot air balloon drawing.
My daughter calls it the “secret light room.” I’ve considered putting a tiny figurine in there just to mess with future homeowners. Maybe a gnome. Or a note that says “you’ve found the time machine.” Tempting, right?
But the truth is, I kind of love it the way it is. Dusty light, silent purpose, and all. It’s one of those little things that makes living in an old house feel like an adventure. You don’t get that in a new build. No one’s discovering forgotten milk doors or heat cabinets in a freshly built townhouse.
Takeaway: Old Houses Hide Cool Stuff
If you live in a home built before the ’50s and find a weird cabinet, don’t rip it out just yet. It might be a 1920s milk door, a call box, or even a forgotten mini heater. Perhaps it was used for the same reason as the 1920s Milk Door in my home.
Sometimes, these things are more than just curiosities—they’re snapshots of a time when life moved a little slower, and your milk arrived like clockwork through the wall.
So yeah, I’m keeping mine. Lightbulb, mystery, and all.