Ours are held on with strapping and few sheetrock screws since they are way overhead but they are very light weight. Picture hangers[1] would work for a small lowdown install or maybe some sort of double stick something... you would have to repaint and patch some holes/paint but its a huge difference. While we where waiting for them to be installed we just had them leaning against the walls like paintings waiting to be hanged. Even that was amazingly different.

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