ZTF18aacdxxf: WD with unusual variation According to the ZTF data, this object shows long-term (months) quasi-periodic fading up to 0.8 mag. It cannot be explained by eclipses by a close companion. It may be caused by periodic obscuration of the WD (such as by a dust cloud), but infrared excess is not particular. Gaia data is compatible with a very low-luminosity star (in agreement with a hot WD). 092311.4 +423633 (2000.0) WDcand G=17.449 Teff=12750 - 092311.396 +423633.61 (2000.0) Gaia_DR2_817461778282929664 plx=6.767(0.127) dismod=5.8 pmra=-9.056(0.173) pmdec=-35.130(0.218) G=17.449 BP=17.410 RP=17.487 092311.396 +423633.59 (2000.0) Gaia_EDR3_817461778282929664 plx=6.787(0.084) dismod=5.8 pmra=-8.985(0.082) pmdec=-35.216(0.069) G=17.432 BP=17.441 RP=17.500 092311.424 +423634.51 (2000.0) GALEX_DR5_6373906452883441211 NUV=17.680(0.037) FUV=18.025(0.071)