An electrical apparatus to connect by cables to a source of alternating current for a domestic or service sector electrical installation, to a load and to a control member, to allow or not allow said source of alternating current to supply said load according to the conducting and non-conducting states taken by the control member, said apparatus comprising: - an in terminal configured to be connected to a pole of said source of alternating current; - an out terminal configured to be connected to said load; - a first command terminal configured to be connected to said command member and a second command terminal configured to be brought to a reference potential, said first command terminal and said second command terminal being configured in order for a predetermined potential difference to be applied to them or not according to said conducting and non-conducting states taken by the command member; - a control member connected to said first command terminal and to said second command terminal, selectively taking an activated state and a deactivated state according to the presence or the absence of said predetermined potential difference between the first command terminal and the second command terminal; and - a switch member connected to said in terminal and to said out terminal taking either a non-conducting state in which it prevents the passage of current between the in terminal, and the out terminal or a conducting state in which it allows the passage of current between the in terminal and the out terminal, said switch member being controlled by said control member via a control transmission configured in order for the transitions between the non-conducting state and the conducting state of the switch member to follow the transitions between the deactivated state and the activated state of the control member or else being configured in order for the transitions between the non-conducting state and the conducting state of the switch member to follow only the transitions from the deactivated state to the activated state; which apparatus is characterized in that it comprises another in terminal configured to be connected to the other pole of said source of alternating current, and comprises a voltage converter (553, 552) an input of which is connected to said in terminal and to said other in terminal in order to be supplied by said source of alternating current, and an output of which is connected to said control member to provide it with a safety voltage, less than 50 V RMS as alternating current or less than 120 V as direct current, said control member being configured to apply said safety voltage between said first command terminal and said second command terminal when they are electrically isolated from each other externally of said apparatus and so as not to apply said safety voltage between said first command terminal and said second command terminal when they are placed at the same potential externally of said apparatus, said control member being in said deactivated state when said first command terminal and said second command terminal are electrically isolated from each other externally of said apparatus and in said activated state when said first command terminal and said second command terminal are placed at the same potential externally of said apparatus, said control member comprising an electrical circuit supplying a logic signal formed by two predetermined voltage thresholds respectively representing the activated state and the deactivated state, said control transmission comprising a logic unit connected to said control member as well as an electromagnetic actuator of said switch member, connected to said logic unit. - an in terminal configured to be connected to a pole of said source of alternating current; - an out terminal configured to be connected to said load; - a first command terminal configured to be connected to said command member and a second command terminal configured to be brought to a reference potential, said first command terminal and said second command terminal being configured in order for a predetermined potential difference to be applied to them or not according to said conducting and non-conducting states taken by the command member; - a control member connected to said first command terminal and to said second command terminal, selectively taking an activated state and a deactivated state according to the presence or the absence of said predetermined potential difference between the first command terminal and the second command terminal; and - a switch member connected to said in terminal and to said out terminal taking either a non-conducting state in which it prevents the passage of current between the in terminal, and the out terminal or a conducting state in which it allows the passage of current between the in terminal and the out terminal, said switch member being controlled by said control member via a control transmission configured in order for the transitions between the non-conducting state and the conducting state of the switch member to follow the transitions between the deactivated state and the activated state of the control member or else being configured in order for the transitions between the non-conducting state and the conducting state of the switch member to follow only the transitions from the deactivated state to the activated state;