My wife also received a call this week to confirm if I was still a resident at our address. No big deal as I am registered and have an up to date 3 year residence visa but useful to know that the PSB and the local police station where I am registered take the issue of foreigners resident in China seriously. The last time she got a call was 48 hours after a visa expired while the renewal was still being processed by the PSB – they don’t waste time if you disappear from their radar.