John,
As others have suggested - how about the light sensing people.
This is a bulb that senses people using Microwaves:
https://uk.gearbest.com/globe-bulbs...MI182SmaqG4AIVybvtCh2b1QeVEAQYAiABEgJi5_D_BwE
and
https://www.amazon.co.uk/s/ref=nb_sb_noss?url=search-alias=aps&field-keywords=Microwave+sensor+bulb&rh=i:aps,k:Microwave+sensor+bulb
They tend to work very effectively, but sometimes too effectively as its microwaves can sometimes look through walls and sense next door or in other rooms.
This one seems to have good reviews:
https://www.amazon.co.uk/Elfeland-S...8330144&sr=8-6&keywords=Microwave+sensor+bulb
SFK
As others have suggested - how about the light sensing people.
This is a bulb that senses people using Microwaves:
https://uk.gearbest.com/globe-bulbs...MI182SmaqG4AIVybvtCh2b1QeVEAQYAiABEgJi5_D_BwE
and
https://www.amazon.co.uk/s/ref=nb_sb_noss?url=search-alias=aps&field-keywords=Microwave+sensor+bulb&rh=i:aps,k:Microwave+sensor+bulb
They tend to work very effectively, but sometimes too effectively as its microwaves can sometimes look through walls and sense next door or in other rooms.
This one seems to have good reviews:
https://www.amazon.co.uk/Elfeland-S...8330144&sr=8-6&keywords=Microwave+sensor+bulb
SFK