Assume $u, v \in \mathcal{D}'(\mathbb{R}^n)$ are distributions with compact support. Denote by $\operatorname{WF}(\bullet) \subset T^*\mathbb{R}^n \setminus 0$ the wavefront set of a distribution $\bullet$. If $\operatorname{WF}(u) \cap \operatorname{WF}(v) = \emptyset$, then their product $uv$ is well defined. If $uv = 0$, does this imply that at an open and dense set of points one of the two distributions vanish, that is, $\operatorname{supp}(u)^c \cup \operatorname{supp}(v)^c \subset \mathbb{R}^n$ is open and dense?

For the background on the wavefront set and distribution theory, see Chapter 8 of Hörmander's book The Analysis of Linear Partial Differential Operators I. For products under the wavefront set condition, see Theorem 8.2.10 of the same book. I've also asked this question on Mathematics StackExchange.

As noted below by Vinicius in the comments, if $u, v \in C^\infty_c(\mathbb{R})$ with $\operatorname{supp}(u) = [-1, 0]$ and $\operatorname{supp}(v) = [0, 1]$, then $uv = 0$ but $\operatorname{supp}(u)^c \cup \operatorname{supp}(v)^c = \mathbb{R}\setminus 0$, so open and dense is the most we can hope for.