It is a fine point whether "visiting" a church means you have become an official member which is definitely an act of disassociation from the WTS.
There has been discussion whether a jw should visit a church for a wedding or funeral on this board. The following is an answer to whether it is forbidden leading to the elder body believing you have disassociated yourself or it is a personal choice.
2002 WT 5/15 p. 28--Questions From Readers
Would it be advisable for a true Christian to attend a funeral or a wedding in a church?
Our taking part in any form of false religion is displeasing to Jehovah and must be avoided. (2 Corinthians 6:14-17; Revelation 18:4) A church funeral is a religious service that likely involves a sermon advocating such unscriptural ideas as the immortality of the soul and a heavenly reward for all good people. It may also include such practices as making the sign of the cross and joining in prayer with the priest or minister. Prayers and other religious exercises contrary to Bible teaching may also be a part of a religious wedding ceremony held in a church or elsewhere. Being in a group where everyone else is engaging in a false religious act, a Christian may find it difficult to resist the pressure to join in. How unwise to expose oneself to such pressure!
What if a Christian feels obligated to attend a funeral or a wedding held in a church? An unbelieving husband, for example, may urge his Christian wife to be with him on such an occasion. Could she join him as a quiet observer? Out of regard for her husband’s wishes, the wife may decide to go with him, being determined not to share in any religious ceremonies. On the other hand, she may decide not to go, reasoning that the emotional pressure of the circumstances could prove to be too much for her, perhaps causing her to compromise godly principles. The decision would be hers to make. She definitely would want to be settled in her heart, having a clean conscience.—1 Timothy 1:19.
In any case, it would be to her advantage to explain to her husband that she could not conscientiously share in any religious ceremonies or join in the singing of hymns or bow her head when prayer is offered. On the basis of her explanation, he may conclude that his wife’s presence could give rise to a situation that might be unpleasant to him. He may choose to go alone out of love for his wife, respect for her beliefs, or a desire to avoid any embarrassment. But if he insists that she go with him, she might go as a mere observer.
Not to be overlooked is the effect our attending a service in a religious building might have on fellow believers. Could it injure the conscience of some? Might their resistance to avoid engaging in idolatry be weakened? “Make sure of the more important things,” admonishes the apostle Paul, “so that you may be flawless and not be stumbling others up to the day of Christ.”—Philippians 1:10.
If the occasion involves a close fleshly relative, there may be additional family pressures. In any case, a Christian must carefully weigh all the factors involved. Under certain circumstances he or she may conclude that no difficulties would arise from attending a church funeral or wedding as an observer. However, the circumstances may be such that by attending, the likely injury to one’s own conscience or to that of others would outweigh the possible benefits of being present. Whatever the situation, the Christian should make sure that the decision will not interfere with his preserving a good conscience before God and men.
(also http://wol.jw.org/en/wol/d/r1/lp-e/2007850
