A siphon for a shower tray, comprising: - a siphon body comprising, on the one hand, a water intake opening by which the water to be discharged from the shower tray penetrates the inside of the body, and on the other hand, a water discharge pipe that is connected to said body, - a housing that is mounted removably on a bottom wall of said body, said housing comprising: • a deformable flexible membrane positioned in the lower part of said housing, said membrane being intended to come into contact with the water entering said body through the opening and to deform by rising inside said body, • a micro-switch that is able to be activated following contact with the deformed membrane that has risen inside the body, • a wired connection between the micro-switch and a connector of a first type connected to the housing and which extends to the outside of said housing, characterized in that the wired connection comprises a connector of a second type fastened to a wall of said body and that is intended to engage mechanically with the connector of the first type during the mounting of the housing, the siphon body /or the housing comprising sealing means to provide the seal around the engagement of the two connectors. - a siphon body comprising, on the one hand, a water intake opening by which the water to be discharged from the shower tray penetrates the inside of the body, and on the other hand, a water discharge pipe that is connected to said body, - a housing that is mounted removably on a bottom wall of said body, said housing comprising: • a deformable flexible membrane positioned in the lower part of said housing, said membrane being intended to come into contact with the water entering said body through the opening and to deform by rising inside said body, • a micro-switch that is able to be activated following contact with the deformed membrane that has risen inside the body, • a wired connection between the micro-switch and a connector of a first type connected to the housing and which extends to the outside of said housing, characterized in that the wired connection comprises a connector of a second type fastened to a wall of said body and that is intended to engage mechanically with the connector of the first type during the mounting of the housing, the siphon body /or the housing comprising sealing means to provide the seal around the engagement of the two connectors. • a deformable flexible membrane positioned in the lower part of said housing, said membrane being intended to come into contact with the water entering said body through the opening and to deform by rising inside said body, • a micro-switch that is able to be activated following contact with the deformed membrane that has risen inside the body, • a wired connection between the micro-switch and a connector of a first type connected to the housing and which extends to the outside of said housing, characterized in that the wired connection comprises a connector of a second type fastened to a wall of said body and that is intended to engage mechanically with the connector of the first type during the mounting of the housing, the siphon body /or the housing comprising sealing means to provide the seal around the engagement of the two connectors.