How do I prove I've moved and the house is now my ex-wifes?

You don't

The bailiff may only take control of goods where the debtor usually lives or carries on a trade or business.^[1]

If a bailiff attends on your ex-wife's property for a debt owed by you, or another, she only needs to tell the bailiff to quietly leave, and the bailiff is now under a duty to leave with all reasonable speed.^[2]

If the bailiff attends on your ex-wife's property, even with a writ or warrant of control with your wife's address on it, the bailiff does not have a power to force entry and search the property to satisfy himself the debtor does not live there.^[3]

If the bailiff takes control of your ex-wife's goods, or vehicle, she can make a third-party claim to controlled goods.^[4][5] Your wife may also recover damages,^[6] together with her costs.^[7][8][9]

^{[1] Paragraph 14(6) of Schedule 12 of the Tribunals, Courts and Enforcement Act 2007
[2] Morris -v- Beardmore, in the House of Lords 09 Jan, 1981
[3] See Neil Tunstall vs Direct Collections Bailiffs Limited (DCBL) and Mr Hussain
[4] Civil Procedure Rule 85.4
[5] See Making third-party claim to controlled goods
[6] Section 3 of the Torts (Interference with Goods) Act 1977
[7] Civil Procedure Rule 46.5
[8] Practice Direction 46.5 Rule 3.1
[9] Civil Procedure Rule 44.2}