The short answer is yes.
There are many Catholics in mixed marriages (A Catholic married to a spouse of another denomination) and to keep peace they attend both Holy Catholic Mass and their spouse’s church service.
Catholics may also question whether they should go to a Wedding or Funeral of a non- Catholic at a non-Catholic church.
It’s important to note here that the Catholic Church does not prohibit attending any non-Catholic church for any reason.
Some may argue that you are giving legitimacy to non-Catholic churches and practices or somehow showing approval of their way of faith. However, most protestant church services are based on prayer, hymns, bible readings and a sermon.
Prayer: Prayer is prayer. Protestant pray Christian Prayers and some of the ones they pray are also used by Catholics. There is absolutely nothing wrong with participating in prayer with anyone, even at a protestant church.
Hymns: Again, hymns are prayers and some of them may be common to what Catholic churches use as well. There is nothing wrong with signing along, in prayer.
Bible Readings: Again, Catholics read the bible, protestants read the bible. You may not agree with some added commentary by the pastor but there is no sin in listening to it in church.
This may be a surprise to some but the Catholic church encourages you to do as you do at a non-Catholic church as it’s members do. This includes preaching and doing the readings if invited by the Pastor. The one exception is that a Catholic must not participate in a non-Catholic communion.
A Catholic must not take communion at a non-Catholic church because it is not a valid Eucharist in the eyes of the Catholic Church. Only an ordained Catholic Priest can see over at valid Eucharist. So, any Eucharist performed by a non-Catholic pastor is invalid by nature. Since Catholics take the validity of taking in the body and blood of Christ in the Eucharist very seriously, it isn’t acceptable to participate in an invalid one.
Here is the Catholic Church’s stand
Sharing in Non-Sacramental Liturgical Worship
116. By liturgical worship is meant worship carried out according to books, prescriptions and customs of a Church or ecclesial Community, presided over by a minister or delegate of that Church or Community. This liturgical worship may be of a non-sacramental kind, or may be the celebration of one or more of the Christian sacraments. The concern here is non-sacramental worship.
117. In some situations, the official prayer of a Church may be preferred to ecumenical services specially prepared for the occasion. Participation in such celebrations as Morning or Evening Prayer, special vigils, etc., will enable people of different liturgical traditions-Catholic, Eastern, Anglican and Protestant-to understand each other’s community prayer better and to share more deeply in traditions which often have developed from common roots.
118. In liturgical celebrations taking place in other Churches and ecclesial Communities, Catholics are encouraged to take part in the psalms, responses, hymns and common actions of the Church in which they are guests. If invited by their hosts, they may read a lesson or preach.