Can I get a bailiff to tell me why they think a debtor lives at my home when he never has?

Yes

Bailiffs cannot enter a property just to satisfy himself the debtor does not live there.^[1]

Bailiffs can only enter the property where the debtor lives.^[2][3]

^{[1] Neil Tunstall vs Direct Collections Bailiffs Limited (DCBL) and Mr Hussain

[2] Paragraph 14(6) of Schedule 12 of the Tribunals, Courts and Enforcement Act 2007

[3] See: Can bailiffs enter my property after I have told him that the person they want doesn't live here?}