Katy Perry Hit by Sparks When Autograph Seeker Touches Transformer, Igniting Elbow newsthirst.

Katy Perry could really hear her fans ‘Roar’ last night … probably screaming out in horrible pain — ’cause one of them touched a transformer and ended up on fire, and nearly disfigured the pop star’s face with sparks.

The singer-songwriter was signing autographs outside “Jimmy Kimmel Live!” Wednesday night … and while making her way down the fence to interact with her fans, sparks exploded in her direction just a couple feet away, causing Katy to duck.

It turns out one of Perry’s fans accidentally touched a transformer — causing a surge of electricity and sparks to spew out … setting the KP fan’s coat on fire.

You gotta see the pics … a small fire burns on the woman’s elbow — and, while she’s finally able to put it out, it’s still smoldering at the end.

Fortunately, no one was hurt too badly … and, Katy even went back to signing autographs later in the evening — though she did so from the safety of her car the second time around.

Perry — who will perform at L.A. FireAid, the relief concert for the devastating wildfires that burned through huge areas of L.A. earlier this month — stopped by Jimmy Kimmel‘s show to talk about her new “The Lifetimes” tour, kicking off April 23 in Mexico City.