You know you’re in Southern California when...

You know you’re in Southern California when . . .

You chance upon a sign in a Burbank public library, as Scott Dewees did, and find that it says:

“EARTHQUAKE WARNING! Watch for falling books. . . .

“In the event of an earthquake, please use extra caution if you are in the vicinity of library bookshelves.”

Or you hear that 40 comics held a “candlelight peace vigil . . . to mark the start of the Mideast peace talks.”

Site of the ceremony: The Laugh Factory in Hollywood.

Halloween is a reminder that L.A. is also haunted by a unique cast of restless spirits. Several famous murder cases left questions unanswered. You might be able to sense the victims’ presence at:

1. Fowler’s Bookstore downtown, where film director William Desmond Taylor stopped on Feb. 1, 1922, to buy two copies of “Inhibitions, Symptoms and Anxiety” by Sigmund Freud. He was shot to death that night by an unknown assailant in his apartment at 404 1/2 S. Alvarado Blvd.

2. A parking lot at 8610 Sunset Boulevard, which was once the site of the rollicking Trocadero Restaurant. Actress Thelma Todd left there on Dec. 14, 1935, and was later found dead in her Packard in a garage above Pacific Coast Highway. Cause of death is still disputed.

3. The Biltmore Hotel lobby, where Elizabeth Short spent three hours on Jan. 10, 1947, possibly waiting for a phone call. When she left, write the authors of “Fallen Angels,” “the doorman saluted her with a tip of his cap and watched her walk down the sidewalk in her red shoes.” She was found murdered five days later and became known as the Black Dahlia.

4. The Venice/Santa Monica boardwalk, trod by gangster Benjamin (Bugsy) Siegel during a visit to the original Jack’s on the Beach diner on July 7, 1947. A few hours later, Bugsy was shot to death in a house in Beverly Hills. The murder was never solved. A lot of people didn’t like Bugsy.

5. The northbound Sunset Boulevard off-ramp of the San Diego Freeway, where some people think socialite Evelyn Throsby Scott is entombed. She disappeared May 16, 1955, from her North Bentley Avenue estate, a few blocks away from the freeway, which was then under construction. Her husband, L. Ewing Scott, was convicted of the murder.

Housing prices are ridiculous here, but still, I. I. Ramirez of L.A. was surprised to come across a postcard sent to “Current Resident.” The address was a post office box.

Bob Tolson of Torrance discovered a parking lot (see photo) whose arrows look as though they were painted by Wily Coyote for the Road Runner.

Traffic was even more jammed than usual Wednesday because of a bedsheet hung over a pedestrian crossing on the Santa Ana Freeway.

“Happy birthday, George,” it said. “Love Faye. My place at 7 p.m.”

Maybe there were a lot of Georges on the freeway that day.

On Pacific Coast Highway, meanwhile, motorized life came to a standstill because of a sighting of . . . dolphins.

“I had 10 or 12 drivers call to say they’d seen them off Big Rock (in Malibu),” said KNX radio reporter Bill Keene. “Later I got another call that they’d been sighted at Sunset (Boulevard). A Channel 2 crew phoned and asked where they could get a shot of them. I told them that at the rate they (the dolphins) were going, they better try to head them off at Redondo Beach.”

miscelLAny:

Seventy-nine years ago this month, Gov. Hiram Johnson vetoed a bill to raise the speed limit in the state from 20 to 30 m.p.h.