I ran into a problem where a ceiling fan was wired to the same circuit as the smoke detector located in the same room. While the ceiling fan was operating, the smoke detector would chirp every so often. Is there a filter of some sort that could be connected in line with the fan to correct this problem? I was discussing this with a coworker and he told me he had the same problem with an attic fan that had been wired to the same circuit as the smoke detector and was causing the same problem.