Each season “The Bachelorcasting director Lacey Pemberton fields thousands of inquiries from enthusiastic single women angling to find true love with the reality show’s leading man.

“At the end of the show we put a card up asking people to submit themselves or nominate somebody,” says Pemberton, whose enormous task is to whittle that pool of thousands down to 25 contestants. “At this point we already have the bachelor in place, and we’ll look at all of the submissions — their photos and tapes, if they’ve submitted that — and we’ll call them about the next step.”

What Pemberton looks for in a potential candidate is a “special spark,” a certain quality that sets her apart from the other would-be fiancees, one of whom will snag a rose and a ring in the season’s always highly anticipated finale.

“There has to be something interesting about the girl that makes me want to watch her, a certain energy,” says Pemberton of the audition process, which lasts about seven months (casting for “The Bachelorette” lasts about five). “I do many long interviews on the phone and in person to see if they might be a natural match for the chosen bachelor.

“You never know what kind of chemistry is going to be there. It’s like going on a blind date. It all looks great paper, but you have no idea what’s going to happen, which is what makes the show so much fun.”

“The Bachelor” exec producer Martin Hilton, who gives the final stamp of approval on all women selected, reveals that many times the women he thinks are going to be perfect wind up “withering” when it comes time for their on-camera interview.

“Going into it we have an image in our heads of what type of person we want to cast,” says Hilton, “but what we wind up liking can be the complete opposite of that original image. We look for people who are able to be themselves, sometimes in spite of themselves. You may love someone but if they’re not able to communicate who they are while the cameras are rolling, it’s never going to work.”

The “sincerity” of the collective cast is what makes “Bachelor” such a grand success, says Hilton.

“These women have to affect both the bachelor and the audience watching them,” he points out. “Each woman chosen must have a certain authenticity and a willingness to fall in love.”

‘The Bachelor’ at 10
‘Bachelor’ brought roses to Warners | Harrison comfy as mentor, matchmaker | Casting director finds the femmes to fit the field | Auds engaged to romance-friendly franchise