Hook: Wall Large (Purple Rectangle)The Holo Sign: Cantina Dancer decoration fits into a large purple rectangle wall hook.
How to Get a Holo Sign: Cantina Dancer Decoration
Cartel Pack Decorations
The Holo Sign: Cantina Dancer decoration can be dropped from Architect's Stronghold Packs, which were released on the Cartel Market and bought with Cartel Coins. Cartel Packs, including the Architect's Stronghold Pack, include a random selection of items from the Architect's Stronghold collection of items. You aren't guaranteed to get a Holo Sign: Cantina Dancer decoration from a Architect's Stronghold Pack, but it is one of the few ways to get a Holo Sign: Cantina Dancer deco apart from buying it on the GTN from another player.
If you're looking to get a Holo Sign: Cantina Dancer, the easiest way to get it is to head to the Galactic Trade Network (GTN) in SWTOR and buy it with credits from another player. If it's very rare and not available on the Cartel Market, you could try buying from the GTN and hope you get it.