@John ******
Although some people don't have a residence back home. On the TM6 forms still handed out at land borders, I always put my Thai address down as my "permanent address". While I own investment properties abroad and I could always put down a family member's address, I'm being honest when I write my address in Thailand on that form and have never been questioned about it (and believe me, I travel a lot). In fact, since the borders re-opened, I've crossed land borders into Thailand probably at least 15 or 20 times and that doesn't include the numerous trips to Europe/Australia/Vietnam/Singapore and other countries I've made by air in that time.
On a visa application, I generally do the same thing (unless it's an actual tourist visa). I guess it depends on the circumstances and if a visa officer actually requested an overseas address be put down, that's when you do (or ask them for clarification should you not have one).