Plenty of signs in the 20m radius, something along this: https://www.thesignshed.co.uk/cdn/shop/products/24-hour-cctv-sign-111878.jpg https://www.thesignshed.c

Plenty of signs in the 20m radius, something along this: https://www.thesignshed.co.uk/cdn/shop/products/24-hour-cctv-sign-111878.jpg https://www.thesignshed.co.uk/cdn/shop/products/24-hour-cctv... Possibly change the usual 'hi' greating to the more appropriate 'sign this release form before coming close or talk!' one.