“We’ve been loving our janitor to death. A do-not-molest sign near the popular lifelike sculpture at the Milwaukee Art Museum has helped a lot, but we can’t seem to keep our hands off the guy.” All that pawing — which is down an estimated 90 percent since the sign went up — has done some damage to Duane Hanson’s “Janitor,” slouched against the wall for the past 36 years.