"There are a lot of unsung heroes in theatre -- and this is an opportunity to open that door for people who want to get involved in other ways."
Mrs Penhale-Cashmore has been acting since age four, when she appeared in a neighbourhood nativity play.
"I think the audience consisted of parents, friends who got blackmailed into coming, and neighbours who wanted to see what the little ratbags were up to," she said.
At 17, she was offered a part in a Harlequin Theatre production -- and clearly remembers her "gorgeous, green taffeta costume".
"I don't remember the play, but I remember that dress -- and quaking in my boots waiting to go on."
After leaving school, she worked as a radio announcer, and was unable to continue acting thanks to night shifts.
She returned to theatre 12 years ago, joining Kapiti Playhouse and, doubting her ability to remember lines, became an enthusiastic member of the backstage crew.
"It was great -- we'd have working bees to sort out the props room, which had suitcases and table settings dating back to the 1900s."
She got up the courage to attend an audition two years ago, landing the role of aged hippy Shirley in Harlequin's sell-out The Old People Are Revolting. Since then she has been an active member of Harlequin, Limelight and Greytown Little Theatres, both on and behind stage, eventually winning Best First-Time Director at this year's Theatrefest national finals for Greytown Little Theatre's A Life Sentence.
Mrs Penhale-Cashmore said she has thoroughly enjoyed all her roles -- the challenges of which she will discuss with the experts on air.
"For example, costuming is challenging as you're getting actors into clothes they wouldn't normally wear. For props, you often have to beg, borrow and improvise.
"Stage crews have to work in the dark to make sure the actors don't trip; if you're front of house, you have to pour heaps of teas in record time.
"But it's wonderful fun, and there are so many opportunities."
The Behind The Scenes show will air every other Monday on Arrow FM at 12.30pm.