Crazy story that someone at the local radio astronomy observatory told me. Context: Radio observatories need to minimize as much radio interference as possible

Crazy story that someone at the local radio astronomy observatory told me. Context: Radio observatories need to minimize as much radio interference as possible. Typically, they are some distance away from population, and people are asked not to use phones within a couple of km of them. Inside the premises no unshielded electronics are allowed. If any are used, you can immediately see the effects on the data being collected by the telescope. Anyway, these guys were getting some sort of strong interference signal at 4 pm every day. They could not figure out where it was coming from. They eventually decided that it was not coming from within, but from somewhere outside the observatory. They got some triangulation equipment out and over the course of several days, finally determined that the signal was coming from a house a couple of km away. So they went over and knocked. Asked the owner what was going on. Turned out, the guy had a electric can opener, and every day at 4 pm he would open a can to feed his dogs. That was the interference signal they were getting all the way to the observatory! Eventually, after some back and forth, they got the guy a new can opener they had vetted to not cause an interference signal.