“In-laws’ house,” “parents-in-law’s house,” or “mother and father-in-law’s house” are all good ways to refer to the house where your wife’s parents live. You can also use “home” in place of “house.” But assuming that your wife lives with you, I don’t know why you would call this house your wife’s house; it may have been her house when she was a child living with her parents, but it no longer is her house.

* Your "wife's house" is either the place that she lives or another place that she owns (even if she doesn't live there). * Your "in-laws' house" is the place that they live (or a place that they own even if they don't live there). * "Home" tends to have positive, warm feelings ("House" is more neutral - not bad, but not as emotional as "home." Also, "house" is more about the building itself while "home" implies people live there.) So if you would like to imply positive warm feelings, you could use the phrases "wife's home" or "in-laws' home." * Your "wife's childhood home" is the place that she grew up - even if neither she nor your in-laws live there now. * "parents-in-law" isn't wrong, but it is uncommon.