Yes, you are reading it correctly and nothing wrong with the spelling. Yes, its a FREE WIFE not WiFi. The advertisement had gone viral after it was published.
“rare offer” — “when you buy this house, you can ask the owner to marry you”,
Read more: http://www.therakyatpost.com/world/2015/03/11/house-for-sale-in-indonesia-with-free-wife/#ixzz3U5F6YQJg
The house belongs to Wina Lia who wanted to sell her house and contacted a property agent to deal with it. Her dealing with the agent was also to help find her a husband too as she is a widow.
The property agent was smart enough the bundle the house and the owner as a package. This is the story that was posted on therakyatpost.