According to the Paroisse protestante de Carouge:

The history of the parish begins in 1804 when the City council of Carouge decided to finance the ministry of a pastor for the Protestant community of the city, which at the same time it had a church council in charge of the management of the group . At that time, the mayor of the town, Monsieur de Montfalcon, fought to restore public worship, which had been banned since 1793 because of the attachment of Savoy (of which Carouge belonged at that time) to France, then revolutionary and anticlerical. In 1806, the Church Council addressed the Ministry of Worship in Paris to formalize the process, to which Napoleon responded positively. Until 1813, the community met at the Chossat house (now Rue du Pont-Neuf 2 bis) but the owner decided to rent his property to a watchmaking factory. The Church Council, unable to find a new place suitable for the community, issued a subscription for the construction of a temple and addressed a petition to the Prefect of Leman to obtain land. This was allotted to them in place of Arms. The following year, the foundations of the temple were laid, but the construction stopped very quickly because of the political upheavals that marked the years 1814-1816: Carouge was again attached to the Kingdom of Sardinia before joining with Geneva in 1815 to form the 22nd canton of the Swiss Confederation with the other “united communes”. The Reformed community of Carouge then joined the Protestant Church of Geneva (1816). Conditions were then in place complete the temple, begun three years earlier. After a study by the Council of State, the original site was abandoned in favor of a plot located at the Place des Bois (present location, today Place du Temple) and the architect François Brolliet was mandated to carry out the project. The temple was inaugurated in 1822.

Sources:

Society of Art History in Switzerland, Ed. Benteli, 1985.

BRULHART, Armand, DEUBER-PAULI, Erica, Arts and Monuments, City and Canton of Geneva.

Christen, Ernest, The Protestant Worship, Ed. Labor, Geneva, 1934.

Dreyfus Fernand, The Temple of Carouge, presentation of a historical, artistic and spiritual place, Labor and Fides, 1999.

Reymond Bernard, Temples of French-speaking Switzerland, discovering heritage, Editions Cabédita, 1997.

Rudaz, Patrick, Carouge, foyer of sacred art, 1920-1945, edited by the City of Carouge, 1998.

I wasn’t able to go inside, but the link above to the parish site provides several pictures of the interior. For a Protestant church in Switzerland it’s surprisingly decorative. They’re usually quite plain.

Taken with my Son-in-Law’s Nikon, D80 and Sigma 18-200mm f3.5-f6.3 lens.