Buisness causal for interview?

Mainly my professional attire is more fall wear. Would it be okay to wear a cardigan to interview even though its summer time. I have a ruffled wrap that I'm wanting to wear with trousers. Or a cardigan with trousers. The interview is for customer service with secure watch ADT system. I'm not sure what to wear because the lady that called me emphasise on business causal wear.