Such a system would be a huge GDPR nightmare. You'd need consent from every visitor to your house to collect data on them, and also you have to delete it if they ever request you to. Best not to even try.
The following processing is outside the scope of the GDPR:
- any activity outside the scope of EU law (e.g., activities of a Member State in relation to national criminal law);
- any activity performed by Member States when carrying out activities in relation to the common foreign and security policy of the EU;
- any activity performed by a natural person in the course of a purely personal or household activity;
- any processing by the EU itself;
and
- any activities performed by national authorities for the purposes of prevention, investigation, detection or prosecution of criminal offences, or performance of judicial functions.