A friend of mine has an electric toothbrush mounted on the wall of her bathroom with a cord running horizontally to the plug in the wall maybe 8 or 9 inches. Her cat jumps up on the vanity in the bathroom and rubs his nose on the wire, so she covered it with one of those hard-plastic cable covers so the cat wouldn't bite it.
His favorite thing in the whole world is to jump up on the counter and rub his nose and cheeks on this cable cover while you scratch him. Whenever I'm over there, if I get up and walk towards the bathroom he runs ahead of me and jumps up on the vanity. Sometimes I'm going there just to scratch him, but other times I make him wait until I'm done with what I went in there for. He puts his face sideways against the cable cover and moves his jaw like he's chewing. He purrs loudly. He can't get enough of this--you could scratch him until all his fur was gone!
The strange thing is that for several weeks this bathroom was out of commission because she was having it redone. As soon as the new vanity was installed the cat would jump up there even though the cable wasn't there. I'd still scratch him, like before, and he'd just put his nose against the wall and work his jaws. He got very unhappy during this time and peed all over her house. but once the toothbrush and cable and cable-cover was back, he's as happy as before.