The phrase "a dim bulb" is correct and usable in written English.
It is typically used to describe someone who is not very intelligent or lacks common sense.
Example: "When he suggested we drive to the beach during a snowstorm, I realized he was just a dim bulb."
Alternatives: "not the brightest" or "a few fries short of a Happy Meal".
For a smart politician, Gov. Gray Davis sure looked like a dim bulb when he put two public relations consultants on state pay at $30,000 a month.
A conventional cathode-ray-tube monitor is something of a dim bulb.
He is standing at one of the apartment's windows, silhouetted by the light of a dim bulb as he gazes at the nighttime traffic streaming down Delancey Street.
She may be something of a dim bulb, but she recognised Margaret as a threat from the off, and she knows that Nucky is slipping away from her.
You're a dim bulb, a fumbling, rattle-grasping baby, unable to digest anything but the watered-down pablum that Tartt or Sebold or Yanagihira are serving; incapable, even, of correctly determining whether or not you liked what you read.
(It will drift within 1.7 light years of a dim bulb called AC+79 3888). And 358,000 years will elapse before Voyager 2 approaches the bright star Sirius.
And she'll do whatever she has to — including seduce a dim-bulb car dealer (Hugh Jackman) — to ensure that her sculpture of the John F. Kennedy assassination wins.
Then, in January 1999, came "The PJs," a fast-moving animated comedy set in the projects (the "PJs" of the title), with a dim-bulb building superintendent as its hero and a supporting cast that includes a Haitian voodoo priestess and a crackhead who lives in a cardboard box.
After the awards had been dished out at the Venice film festival last September, a dim-bulb journalist asked jury president Alfonso Cuarón if he might be accused of regional bias for handing the top honours to "films from your continent".
The old guard will strike back whenever it can, whether proposing steel import quotas or trying to close our borders in order to protect a dim-bulb, overpaid American engineer from an ambitious Indian or Taiwanese.
An elderly couple sit, static and wan, under a single dim bulb and a tangle of mismatched chairs suspended at ceiling height.
