Halloween: annual holiday that mandates dressing like a freak and acting like a deviant. Usually turns into a weeklong affair.

DO
“I’m from the ’70s” Costume Party
What: The name says it all: Dress like you’re from the era that glorified the lude.
Why: Do John Ritter proud.
When: Fri., 8 p.m.-2 a.m.
Where: Johnny Brenda’s, 1201 N. Frankford Ave. (215-739-9684).

DANCE
Bouffant Bangout
What: Monthly party with ’50s and ’60s rock ’n’ roll and psych surf. You, in a bouffant, drink, dance, and enter limbo contests.
Why: Gear up for Friday.
When: Wed., 10 p.m.-2 a.m.
Where: The Barbary, 951 Frankford Ave. (215-634-7400).

RAID
Your Friends’ Closets
What: A costume treasure trove awaits inside your pals’ sacred wardrobes. Mix, match, wear, and return.
Why: It’s free.
When: Start today!
Where: We bet their numbers are in your cell.

SEE
Ghosts and Shadows
What: An eerie art installation inspired by parts of Brolo Hill Farm.
Why: The highbrow answer to Terror Behind the Walls.
When: Thru Jan. 2. Daily, 9 a.m.-5 p.m.
Where: The Schuylkill Center, 8480 Hagys Mill Rd. (215-428-7300).

BUY
Pumpkins
What: The big orange fruit that you carve, make into pie, or simply let rot on your desk.
Why: Look, if you don’t do it, everyone will talk about how much of a downer you are.
When: Varies by neighborhood.
Where: The farmers market.