Campbell, 63, of Auckland, has hesitated to tell this story before but two months later has told the Herald about the horror of waking up to a rat eating his face.
It happened about two months ago in his Khyber Pass studio apartment after he'd taken his usual sleeping pill, which he helps manage his insomnia.
"I wondered what the hell was going on and just felt fluid pouring down my face. So I went and looked in the mirror and I looked like Dracula.
"Mate, from the top of my lip to around the bottom, it had bitten me. It must have smelled my breath or something."
In a bit of a stupor from the sleeping pill and the early hour, Campbell cleaned up his face and went back to sleep.
"But next minute, the guy's having a go at my thumb.
"He tried to eat my thumb, I swear to God.
"That was it. I was too tired, too bloody stupid to do anything so I came and slept on the couch and turned over the bed, but under it was all bloody rat shit."
The next morning he woke-up "shit-scared" and went to Auckland Hospital for a check-up, a tetanus shot and had the puncture marks on his lips tended to.
"It must have been quite a big rat because it grabbed my whole mouth."
The doctors told him they'd never seen anything like it before and people came specifically to see him.
The actor - who has appeared in Hercules and Shortland St, was the "Vince Martin of New Zealand" for Pit Stop and various other commercials - is still kicking himself he didn't get a picture of his face at the time.
And when asked to describe the pain, Campbell could only say: "Well, I've never had my face eaten before.
"From being in a dead sleep to actually wake-up with the pain then glimpse the rat.
"I thought I was in a nightmare."
Campbell has lived in the units opposite University of Auckland's Newmarket campus - which used to be one of Lion's breweries - for about three years.
One of his neighbours told him that when the university took over the site, all the rats migrated across the road.