Invariant means for the wobbling group

Given a metric space $(X,d)$, the wobbling group of $X$ is the group of bijections $g:X\to X$ satisfying $\sup\limits_{x\in X} d(g(x),x)<\infty$\mathrm{.}Westudyalgebraicandanalyticpropertiesof$W(X)$ in relation with the metric space structure of $X$, such as amenability of the action of the lamplighter group $ \bigoplus_{X} \mathbf Z/2\mathbf Z \rtimes W(X)$on$\bigoplus_{X} \mathbf Z/2\mathbf Z$ and property (T).